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In this article, we will address the following: How to use xlsxwriter to save Excel How to save multiple data frames to worksheets using Python How do use Python to stylize the Excel formatting How to ensure that specific data types such as datetime, integer, string, and floating data are saved accurately when using Python and xlsxwriter to save a data frame to Excel Question Description: Imagine that you have the following 2 data frames and you want to save them into one Excel file with different sheets and stylize the Excel formatting. Solution: Save Excel through xlsxwriter 1. Import xlsxwriter package and create Excel file Use to create a new Excel file. Workbook # import package
import xlsxwriter
# create excel file
workbook = xlsxwriter.Workbook("new_excel.xlsx") 2. Create two sheets Use to create a sheet because we have two data frames that need to be saved, we have to create two sheets. add_worksheet worksheet1 = workbook.add_worksheet('df1_sheet')
worksheet2 = workbook.add_worksheet('df2_sheet') 3. Set header format and save the header First, we set the header format and use to save our header. .write_row has four arguments, they are: worksheet.write_row(row, col, data, cell_format). .write_row header_format = workbook.add_format({
 'valign': 'top',
 'fg_color': '#002060',
 'border': 1,
 'font_color': 'white'})
worksheet1.write_row(0, 0, df1.columns, header_format)
worksheet2.write_row(0, 0, df2.columns, header_format) 4. Create some format : This method is used to define the numerical format of a number in Excel. It controls whether a number is displayed as an integer, a floating point number, a date, a currency value, or some other user-defined format. format.set_num_format() The numerical format of a cell can be specified by using a format string or an index to one of Excel’s built-in formats, for more information you can check xlsxwriter-format For example: represents , so 14 m/dd/yyyy format.set_num_format(14) = format.set_num_format('m/dd/yyyy') # set datetime format "m/d/yy"
format_datetime = workbook.add_format({'border': 1})
format_datetime.set_num_format(14) # based on above table, 14 means "m/d/yy"
format_datetime.set_font_size(12) # set font size

# set General format
format_general = workbook.add_format({'border': 1})
format_general.set_num_format(0) # 0 means general
format_general.set_font_size(12)

# set integer format "0"
format_integer = workbook.add_format({'border': 1})
format_integer.set_num_format(1)
format_integer.set_font_size(12)

# set float format "0.00"
format_float = workbook.add_format({'border':1})
format_float.set_num_format(2)
format_float.set_font_size(12)

# set integer format with thousands separators "#,##0"
format_integer_separator = workbook.add_format({'border': 1})
format_integer_separator.set_num_format(3)
format_integer_separator.set_font_size(12)

# set percent format "0.00%"
format_percent = workbook.add_format({'border':1})
format_percent.set_num_format(10)
format_percent.set_font_size(12) 5. Save the data into Excel with cell_format The zero index row already saved our header, so we start from one index row(set the first argument to 1) # .write_column(row, column, data, cell_format)

worksheet1.write_column(1, 0, df1.iloc[:, 0], format_datetime)
worksheet1.write_column(1, 1, df1.iloc[:, 1], format_integer)
worksheet1.write_column(1, 2, df1.iloc[:, 2], format_integer_separator)
worksheet1.write_column(1, 3, df1.iloc[:, 3], format_general)
worksheet1.write_column(1, 4, df1.iloc[:, 4], format_float)
worksheet1.write_column(1, 5, df1.iloc[:, 5], format_percent)
worksheet2.write_column(1, 0, df2.iloc[:, 0], format_datetime)
worksheet2.write_column(1, 1, df2.iloc[:, 1], format_integer)
worksheet2.write_column(1, 2, df2.iloc[:, 2], format_integer_separator)
worksheet2.write_column(1, 3, df2.iloc[:, 3], format_general)
worksheet2.write_column(1, 4, df2.iloc[:, 4], format_float)
worksheet2.write_column(1, 5, df2.iloc[:, 5], format_percent) 6. Set column width For a better display of the data, we can also use to set the column width. .set_column worksheet1.set_column('A:A', 15)
worksheet1.set_column('B:B', 15)
worksheet1.set_column('C:C', 15)
worksheet1.set_column('D:D', 15)
worksheet1.set_column('E:E', 15)
worksheet1.set_column('F:F', 15)
worksheet2.set_column('A:A', 15)
worksheet2.set_column('B:B', 15)
worksheet2.set_column('C:C', 15)
worksheet2.set_column('D:D', 15)
worksheet2.set_column('E:E', 15)
worksheet2.set_column('F:F', 15) 7. Finish workbook.close() Below is the full Python code that utilizes the xlsxwriter package to save two data frames into an Excel file with different sheets and stylized formatting. The code begins by importing the necessary pandas and xlsxwriter packages. Then, it defines the two data frames, df1 and df2. It proceeds to create a new Excel file and two sheets using and functions, respectively. xlsxwriter.Workbook add_worksheet Following this, the code sets the header format, defines various cell formats for different data types, and writes the data into the Excel file with the specified cell formats. Finally, it sets the column widths, closes the workbook, and thus completes the process of saving the data frames into an Excel file. # generate two dataframes 
import pandas as pd

df1 = pd.DataFrame(
    {'Date': ['2022/12/1', '2022/12/1', '2022/12/1', '2022/12/1'], 'Int': [116382, 227393, 3274984, 438164],
     'Int_with_seperator': [1845132, 298145, 336278, 443816], 'String': ['Tom', 'Grace', 'Luca', 'Tessa'],
     'Float': [98.45, 65.24, 30, 80.88], 'Percent': [0.8878, 0.9523, 0.4545, 0.9921]})
df2 = pd.DataFrame({'Date': ['2022/11/1', '2022/11/1', '2022/11/1', '2022/11/1'], 'Int': [233211, 24321, 35345, 23223],
                    'Int_with_seperator': [925478, 23484, 123249, 2345675],
                    'String': ['Apple', 'Huawei', 'Xiaomi', 'Oppo'], 'Float': [98.45, 65.24, 30, 80.88],
                    'Percent': [0.4234, 0.9434, 0.6512, 0.6133]})
print(df1)
print(df2)

# import package
import xlsxwriter
# create excel file
workbook = xlsxwriter.Workbook("new_excel.xlsx")

# create two sheets
worksheet1 = workbook.add_worksheet('df1_sheet')
worksheet2 = workbook.add_worksheet('df2_sheet')

# set header format and save the header
header_format = workbook.add_format({
 'valign': 'top',
 'fg_color': '#002060',
 'border': 1,
 'font_color': 'white'})
worksheet1.write_row(0, 0, df1.columns, header_format)
worksheet2.write_row(0, 0, df2.columns, header_format)

# set datetime format "m/d/yy"
format_datetime = workbook.add_format({'border': 1})
format_datetime.set_num_format(14) # based on above table, 14 means "m/d/yy"
format_datetime.set_font_size(12) # set font size

# set General format
format_general = workbook.add_format({'border': 1})
format_general.set_num_format(0) # 0 means general
format_general.set_font_size(12)

# set integer format "0"
format_integer = workbook.add_format({'border': 1})
format_integer.set_num_format(1)
format_integer.set_font_size(12)

# set float format "0.00"
format_float = workbook.add_format({'border':1})
format_float.set_num_format(2)
format_float.set_font_size(12)

# set integer format with thousands separators "#,##0"
format_integer_separator = workbook.add_format({'border': 1})
format_integer_separator.set_num_format(3)
format_integer_separator.set_font_size(12)

# set percent format "0.00%"
format_percent = workbook.add_format({'border':1})
format_percent.set_num_format(10)
format_percent.set_font_size(12)

worksheet1.write_column(1, 0, df1.iloc[:, 0], format_datetime)
worksheet1.write_column(1, 1, df1.iloc[:, 1], format_integer)
worksheet1.write_column(1, 2, df1.iloc[:, 2], format_integer_separator)
worksheet1.write_column(1, 3, df1.iloc[:, 3], format_general)
worksheet1.write_column(1, 4, df1.iloc[:, 4], format_float)
worksheet1.write_column(1, 5, df1.iloc[:, 5], format_percent)
worksheet2.write_column(1, 0, df2.iloc[:, 0], format_datetime)
worksheet2.write_column(1, 1, df2.iloc[:, 1], format_integer)
worksheet2.write_column(1, 2, df2.iloc[:, 2], format_integer_separator)
worksheet2.write_column(1, 3, df2.iloc[:, 3], format_general)
worksheet2.write_column(1, 4, df2.iloc[:, 4], format_float)
worksheet2.write_column(1, 5, df2.iloc[:, 5], format_percent)

worksheet1.set_column('A:A', 15)
worksheet1.set_column('B:B', 15)
worksheet1.set_column('C:C', 15)
worksheet1.set_column('D:D', 15)
worksheet1.set_column('E:E', 15)
worksheet1.set_column('F:F', 15)
worksheet2.set_column('A:A', 15)
worksheet2.set_column('B:B', 15)
worksheet2.set_column('C:C', 15)
worksheet2.set_column('D:D', 15)
worksheet2.set_column('E:E', 15)
worksheet2.set_column('F:F', 15)

workbook.close() Thank you for taking the time to explore data-related insights with me. I appreciate your engagement. If you find this information helpful, I invite you to follow me or connect with me on . Happy exploring!👋 LinkedIn Also published . here

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The phrase “complexity is the enemy of security” has floated around IT teams for decades. The general belief is that an overly complicated approach to will lead to greater vulnerabilities. Since most organizations are scrambling to advance their defenses against new threats, the debate on whether it is true matters now more than ever. cybersecurity What Does “Complexity Is the Enemy of Security” Mean? The “complexity is the enemy of security” mantra means the more complicated a system is, the more challenging it will be to safeguard against threats. The more components, dependencies, integrations, and configurations an IT team has, the more time they’ll spend maintaining, managing, and securing everything. Instead of sunsetting and replacing legacy systems, many organizations keep adding to their tech stack. Layering security to strengthen defenses for years. Rather than navigate intricate dependencies and configurations, they adopt more technology. has been the industry-standard approach While many IT teams believe adapting is essential to security, most can’t upgrade all their technology whenever a new threat appears. Instead, they rely on well-established systems. However, having a mix of legacy and modern devices because it creates gaps — one of the reasons people consider complexity the enemy. increases the risk of cyberattacks Why Cybersecurity Complexity Exists Most IT teams manage dozens of software, hardware, vendors, and apps. Globally, every business on average in 2022. That number has risen annually for nearly a decade and will likely continue increasing for years. used 130 separate SaaS applications Even though the general sentiment of complexity being detrimental has existed for ages, IT teams continue to layer security. They’ve mainly had to because it’s the only way they can safeguard against constantly changing cyberthreats. Organizations to keep pace with the ever-evolving threat landscape. With the sudden rise of technologies like artificial intelligence and the Internet of Things, professionals have had to modernize or risk being vulnerable. must constantly adapt How Does Cybersecurity Complexity Impact IT Teams? Cybersecurity complexity has ripple effects upstream and downstream — it affects end users as much as chief information security officers. That said, the IT team feels the brunt of the impact. They must manage an increased attack surface, constant updates, misconfigurations, troubleshooting, unintended component interactions, and convoluted compliance monitoring. Consequently, IT professionals experience fatigue. Many neglect security in response, increasing their vulnerabilities. Research shows human error causes in the United States and the United Kingdom. People are already prone to careless and malicious behavior, so these consistently large workloads aren’t ideal. 90% of cybersecurity incidents When systems become too complicated to manage, people naturally look for convenient workarounds. For example, they might skip pressing updates, refuse to implement multifactor authentication, or ignore essential alerts. As a result, their overall security suffers. Attackers have used complexity to their advantage. They’ve exploited outdated systems, negligence, and misconfigurations to find gaps and vulnerabilities. Notably, IT professionals might also have more difficulty locating threats when maintaining dozens of security tools simultaneously. Is “Complexity Is the Enemy of Security” True? On the one hand, the phrase “complexity is the enemy of security” is true because overly complicated setups require more effort to maintain. They inherently create an increased attack surface and have a higher probability of failure. The chance for human error rises because people find workarounds to make their lives more convenient. Additionally, complexity means more overhead and operational costs. The more organizations spend to maintain and manage their systems, the less they’ll have to strengthen security more meaningfully. The same concept applies to time — the longer they focus on upgrades and troubleshooting, the less attention they can devote to more pressing concerns. On the other hand, complexity doesn’t automatically translate to difficulty. Often, complicated configurations result in more straightforward management for end users. Additionally, multilayered security offers comprehensive protection from every potential threat. Moreover, having more hardware, software, and applications allows IT teams to adapt to any threat. Continuously layering security as the cybersecurity landscape evolves helps them fine-tune their defenses. Even if they only have redundant systems, they’re automatically more protected because they have backups. Complexity isn’t inherently harmful to IT teams. Instead, subpar planning is the real threat. Professionals who balance their technology needs with manageability and convenience can better protect themselves. Sometimes, layering security translates to simplicity. Complexity Doesn’t Translate to Better Security For years, IT teams have upped their investments in security. Worldwide spending on cybersecurity , an increase of 12.1% compared to 2022. However, none of those expenses have meaningfully slowed cyberthreats. reached $219 billion in 2023 Rather, cybercriminals have become more brazen and have launched more attacks. Annual data breaches in 2019 to 1,802 in 2022. The fact these cybersecurity incidents increased by 40% in the same period that spending rose $30.3 billion proves the industry’s approach to layering security isn’t working out as expected. went from 1,279 instances Even though most organizations have been spending more for years, they haven’t made a meaningful dent in the threat landscape. It seems complexity doesn’t result in marked improvement by itself. Although subpar planning is the real threat, IT teams shouldn’t layer security just to modernize or adapt. Organizations can strengthen security with proper planning. Instead of continuously adopting a multilayered approach because it’s easier than reconfiguring or phasing out legacy systems, they must prioritize. Whether they need to safeguard personally identifiable information, proprietary data or critical systems, they must build their strategy around protecting core systems instead of expanding to fill every potential gap. Organizations Can Make Complexity Work for Them Organizations have grown too comfortable, making their systems overly complicated to compensate for their vulnerabilities. Instead of spreading themselves thin by expanding their protections to cover every endpoint, they should seriously consider reprioritizing. Strengthening the most critical systems and dropping unnecessary hardware can be very rewarding. Even though having dozens of tools and systems isn’t inherently risky, simplifying their approach to security will undoubtedly improve IT professionals’ work lives and increase organizational safety. Although many IT leaders believe they must continue adopting new technology to protect themselves against the ever-evolving threat landscape, balancing complexity and manageability is much safer in the long term.

Is Complexity the Enemy of Security?

“ ” What AI model maker would take the risk to make any powerful model if they could be responsible for anything someone might possibly do with it? This – author, futurist, engineer, and systems architect. I’ve had the pleasure of conversing with him a couple of times, first about the , which he leads, and then about . I’ve noticed some of Jeffries’ recent shares about OpenAI, AI doomers, and upcoming regulations, most notably the EU AI Act. question is posed by Dan Jeffries AI Infrastructure Alliance Generative AI I’ve and generally consider it and its tiered approach a step in the right direction. I also thought that introducing the notion of general-purpose AI systems powered by foundation models made sense. As far as I understood, uses of the system may or may not be regulated, depending on how they are categorized. covered the EU AI Act https://hackernoon.com/what-the-eu-ai-act-effect-means-for-the-bloc?embedable=true In addition, there are specific requirements for foundation models, including for things such as data governance and compute. That means and will probably converge toward compliance. foundation models can be evaluated In , Jeffries makes some good points about fearmongering and innovation. He also lays out a simple framework for regulation, which looks reasonable. It certainly made me think long and hard about finding the right balance between innovation and regulation in AI. this post How can we find the right balance between innovation and regulation in AI? I’ve laid out what i believe are some important questions to ask here are, along with answers i’ve arrived at. 1. If foundation models can be used in a number of settings, including in ones that would be regulated if dedicated models were developed for them, does it make sense to regulate foundation models, too? Probably yes, and we don’t need to include AI doomerism in this conversation. Let’s take surveillance, for example. I picked the example on purpose because you’d think surveillance would be regulated. It is not, and that’s a good point Jeffries makes – it probably should be. If surveillance is regulated, and foundation models can be used for that or any other regulated application, I don’t see why they should be exempt from regulation. However, there are lots of nuances here in defining “use.” See the next point. 2. What is the threshold that distinguishes a foundation model from a non-foundation one? Capabilities, but it’s not straightforward at all. I’ve seen ideas like , which I don’t think will work. using the amount of compute used to train models as a proxy for capabilities being floated If a model can be *directly* used to power regulated applications such as surveillance, then it should be subject to the same regulation dedicated models are. The key word here is *directly*. A surveillance system contains many components, software, and hardware, from cameras to databases and image recognition algorithms. None of these should or could be regulated in isolation. But if a model does have image recognition capabilities and can *directly* connect to a camera and a database and automate surveillance, then it makes sense to regulate it. Emphasis on *automate* here. See the next point. 3. If foundation models are to be regulated, what type of oversight should be applied to them, and how will it be enforced? High-risk systems, as defined in the EU AI Act, seem about right. There’s a syllogism to unpack here. The EU AI Act originally adopted the definition proposed by the OECD regarding what it applies to: “The OECD defines an Artificial Intelligence (AI) System as a machine-based system that can, for a given set of human-defined objectives, make predictions, recommendations, or decisions influencing real or virtual environments”. The , but the emphasis remains on decisions. That is the whole point of specifically regulating AI systems – the automation part. A camera or a database can be used by people to make decisions. An AI system can make decisions autonomously. OECD has issued a revised definition In the EU AI Act, : Unacceptable risk systems are banned entirely (although some exceptions apply), high-risk systems are subject to rules of traceability, transparency, and robustness, low-risk systems require transparency on the part of the supplier and minimal risk systems for which no requirements are set. AI systems are classified into 4 categories according to the perceived risk they pose https://linkeddataorchestration.com/2022/05/12/the-eu-ai-act-what-you-need-to-know/?embedable=true Requiring traceability, transparency, and robustness from foundation models seems reasonable. , so we have an idea of what this would look like in practice. Stanford researchers have evaluated foundation model providers like OpenAI and Google for their compliance with the EU AI Act It does not look like asking foundation model developers to provide this information would impose excessive overhead or stifle competition. But it does look like having them comply with these requirements would create a level playing field and benefit everyone using them directly or indirectly. 4. Should there be a distinction between regulating big tech models vs. open source models? Probably not, counter-intuitive as it may seem. First, because it’s hard to draw a line, case in point – does OpenAI count as big tech, for example? Second, because big tech, open source, and innovation are not mutually exclusive. Case in point – Meta, IBM, and the . newly announced AI Alliance Third, because . Case in point – and . open source is also a nuanced concept Llama AI model weights The question of whether governments should regulate open foundation models and how to do so is the key to finding the right balance between innovation and regulation in AI. Experts from industry, academia, and government convened to outline a path forward at a . Princeton-Stanford workshop on How to Promote Responsible Open Foundation Models This is the first in a series of short posts about important questions posed by people who think deeply and far about technology and its impact, focusing on AI in particular. The idea is to introduce a question and tease some answers as provided and/or inspired by the person who posed the question. 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Scientific American Supplement, No. 711, August 17, 1889, by Various, is part of the HackerNoon Books Series. You can jump to any chapter in this book . PLATINOTYPE PRINTING. here PLATINOTYPE PRINTING. Platinotype, which may be considered to be the most artistic of photographic printing processes, may be separated into its three modifications—the hot bath and cold bath, in which a faintly visible image is developed, and the Pizzighelli printing-out paper. The hot bath process, again, may be divided into the black and white and sepia papers. I intend to give you a rough outline of the preparation of the paper and working of these modifications, concluding by demonstrating the hot bath method, and handing around prints by it. Platinotype may almost be styled an iron printing process, for, while no trace of iron or its salts is found in the finished print, certain salts of iron are mixed with the platinum salt, which is platinum combined with two atoms of chlorine (PtCl2), as a means for readily reducing it; this, however, cannot be effected without the presence of neutral oxalate of potash, hence the use of the oxalate bath. There is no platinum in the paper for the cold bath process, it being coated with ferric oxalate mixed with a very small quantity of chloride of mercury—somewhere about one grain to an ounce of ferric oxalate solution. When dry it is ready for exposure, which is about three times less than with silver printing. It is absolutely necessary to store all papers for platinum printing in an air-tight tin containing chloride of calcium, which must be dried by heating from time to time. For the cold bath, however, it is important to have moisture present during printing, or it may be after printing and before development. If the paper is left in a dampish room for fifteen minutes, it should be sufficient. Prints made by exposing damp paper, or damping dry paper just before development, must be developed within one hour if the maximum of vigor is desired; by delaying the development some hours, the prints in the meantime being stored in a drawer so that they may retain their moisture, an increase of half tone and warmth of color will be obtained. If it should be necessary to delay development for a day or two, the prints must be dried before a fire soon after being removed from the frames, and then stored in a calcium tube until wanted for development. While printing, the lemon color of the paper receives a grayish colored image, which, although faint, can, with practice, be judged as easily as silver printing. The developer consists of oxalate of potash and potassic chloro-platinite—about thirty grains of the platinum salt to half an ounce of oxalate forming about six ounces of solution; a great many variations, however, may be made in the proportions of platinum salt and oxalate, and different effects secured. Development is effected by sliding the print face downward on to the developer, which must be rocked after the development of each print to avoid scum marks. To clear the prints they are washed in three or four baths of a weak solution of hydrochloric acid after leaving the developer, to remove all traces of the iron salts, and finally washed for a quarter of an hour in three changes of water; they are then finished, and may be dried between clean blotting paper. Pizzighelli's process differs from the above in being one that prints fully out in the frame without development; the paper contains the platinum and iron salts as well as the developer, and so prints and develops at the same time. Although excellent prints can be produced with it, for general work the results of the paper, as at present made, will not compare with the hot and cold bath processes. It is, however, excellent for printing from very dense negatives, and occasional negatives that seem extremely suitable for it. The paper should be breathed on before printing, as if it is quite dry the printing will be very slow and irregular. The best conditions for the preparation of the paper have scarcely been decided upon yet, and it is not quite fair to judge the process. The prints are cleared in the acid baths and washed for about a quarter of an hour. The sepia and black hot bath processes are much alike in the general treatment. There are, however, some special precautions to be observed with the sepia paper, the chief being to protect it from any but the faintest rays of light; the prints, unlike the black ones, may be affected by light when in the acid bath. A special solution must be added to the developer to keep the lights pure. Over-exposure cannot be corrected by using a cooler bath, as is the case with the black prints, and the paper does not remain good so long. The paper for the black prints by the hot bath process is washed with a mixture of potassic platinous chloride and ferric oxalate, the proportion being about sixty grains of the platinum salt to one ounce of the iron solution. It will not keep good longer than twenty minutes or so, and must be applied to the paper directly after mixing. The ferric oxalate in the paper is reduced by the action of light to ferrous oxalate, which forms the faint visible image; this, when the paper is floated on the oxalate of potash bath, is capable of reducing the platinum salt in contact with it into metallic platinum; but the ferric salt, which remains unaltered, has no action on the platinum salt, leaving these parts, which represent the high lights of the print, untouched. The ferric oxalate is removed by the acid baths which follow the development. A good temperature for development is 150° Fahr., and when using this so much detail should not be apparent as when printing for the cold bath process, in which all the detail desired should be very faintly visible. There are, however, many methods of exposing the paper and developing it, and no fixed rule can be made, but the development must in every case be suited to the exposure or the result will be a failure. For instance, the paper may be printed until all detail is visible, but a very much cooler development must be used, say 80° or 90°; on the other hand, a slightly short exposure may be given, and a temperature of 180° to 200° used. 150° should be taken as the normal temperature, and kept to until some experience has been gained, as employing all temperatures will lead to confusion, and nothing will be learned. Some negatives require a special treatment, and both printing and development must be altered, while for a very dense negative the paper may be left out in a dampish room for some time. It will then print with less contrast and more half tone. A thin negative is better printed by the cold bath process, but negatives should be good and brilliant for platinotype printing. Any one taking up platinotype and getting only weak prints would do well to look to his negatives instead of blaming the paper, as the high lights should be fairly dense, and the deep shadows nearly clear glass. Time for complete development should always be allowed; with a hot bath fifteen seconds will be sufficient, but if a cooler development is used, or the prints are solarized in the shadows, more time should be allowed. When the deep shadows are solarized, or appear lighter than surrounding parts, a hot and prolonged development is required to obtain sufficient blackness, as they have a tendency to look like brown paper. I have found breathing on solarized shadows useful, as in the presence of slight moisture they begin to print out and become dark before development, getting black almost directly the print is floated on the oxalate. Three or four acid baths of about ten minutes each are used, and the prints are washed as before. The process throughout takes much less time than silver printing, and can be kept on all the winter, when it is nearly impossible to print in silver. Prints can be developed in weak daylight or gaslight, and prolonged washing is dispensed with.— N.P. Fox, reported in Br. Jour. of Photo. A communication to the North London Photographic Society. About HackerNoon Book Series: We bring you the most important technical, scientific, and insightful public domain books. This book is part of the public domain. Various (2004). Scientific American Supplement, No. 711, August 17, 1889. Urbana, Illinois: Project Gutenberg. Retrieved https://www.gutenberg.org/cache/epub/16972/pg16972-images.html This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at , located at . www.gutenberg.org https://www.gutenberg.org/policy/license.html

PLATINOTYPE PRINTING

Scientific American Supplement, No. 799, April 25, 1891 by Various, is part of the HackerNoon Books Series. You can jump to any chapter in this book . THE RAISING OF THE ULUNDA. here THE RAISING OF THE ULUNDA. Shortly after the recovery of the Ulunda, below described, the North American and West Indian squadron of the Royal Navy visited Halifax, Nova Scotia. The simple and novel means adopted for raising the ship attracted considerable attention among the officers of the fleet, and by way of stimulating the studies of the junior officers in this branch of their duties, a prize was offered for the best essay on the subject, to be competed for by the midshipmen of the various ships. The essays were adjudicated upon by Captain W.G. Stopford, of the flag ship—H.M.S. Bellerophon—and the first prize was awarded to the following paper, written by Mr. A. Gordon Smith, of H.M.S. Canada. The article needs no apology, but it is only just, says the , to mention the fact that the writer is not yet eighteen years of age. Engineer The steamship Ulunda, on the remarkable raising and recovery of which this paper is written, is an iron screw ship of 1,161 tons, until lately belonging to the Furness line. It is a sister ship to the Damara, of the same company, and was built and engined by Alex. Stephens, shipbuilder and engineer, at Glasgow, being fitted with compound vertical engines, of 200 nominal horse power, having two cylinders of 33 inches and 66 inches diameter respectively, which are capable of sixty-five revolutions per minute, and give a speed of twelve knots an hour. For supplying steam to the engines there are two return-tube boilers, each having three furnaces, and there is also a donkey boiler, which is used in harbor for working the four steam winches on deck. She is divided into seven watertight compartments by athwartship bulkheads. The foremost one is the usual collision bulkhead. Between this and the foremost engine room bulkhead are Nos. 1 and 2 holds, separated by a watertight bulkhead. Abaft the after engine room are two more holds, divided in the same manner as the forward ones, and astern is another compartment, in which all stores are kept. Coal bunkers form a protection for the engines and boilers. Fore and aft the ship, as low down as possible, are a number of ballast tanks, which can be filled with or emptied of water as occasion requires to alter the trim of the ship. Extending over all holds there is a strong iron lower deck, about 8 feet below the upper deck, which is pierced with a hatch over each hold immediately under a corresponding hatch in the upper deck, for stowing and unstowing cargo. In the engine room there are six steam pumps, two of them bilge pumps, worked by the main crossheads, for clearing the engine room of water. For pumping out the ballast tanks there are two more, which have their own independent engines. The remaining two are for various purposes. Besides these there are several hand pumps on the upper deck. Having been built in 1885, the Ulunda is almost a new ship, and has been used principally as a cargo steamer, though she is provided also with a saloon and staterooms for a few passengers. She was on her way from St. John, New Brunswick, to Halifax, when during a thick fog she struck on Cowl Ledge, a reef between Bryer and Long Islands, on the southwest coast of Nova Scotia, about half a mile from the shore. The cause of the disaster was probably one of the strong tide eddies which exist in the Bay of Fundy, and which had set her in toward the shore. It was calm at the time, and she was making seven knots an hour; and, being close to the shore, leads should have been going in the chains. Had this precaution been taken, very probably she would have been able to stop or anchor in time to avert this catastrophe. There was no cargo on board, it being intended to ship one at Halifax for London. When ashore on this reef she was sold by public auction at Halifax, and fell to a syndicate of private individuals for £440. These gentlemen at once decided to raise her if possible, transport her into dock, and repair her. They commissioned Captain Kelly, of the Princess Beatrice, a ship then in harbor, to visit her and see what could be done for that purpose. He went with a hired crew to Annapolis, and from thence proceeded to the steamer by means of a tug, a distance of about forty miles. When they arrived they found the Ulunda with her head to sea, and her stern in only 2 ft. of water at low tide, with a list of 30 deg. to port and her foremast broken short off. At high tide the water flowed over the upper deck. On examination, the engine room was found full of water, which did not rise and fall with the tide, showing that it had been filled at high tide through its skylight. No. 3 hold was also full, but had a slight leak, which was shown by the water falling slowly at low tide and rising in the same manner at high water. The other three holds were hopelessly leaky. Upon investigation, it was decided to pump out the engine room compartment and No. 3 hold, and to make the iron lower deck watertight over the remaining holds. For this purpose three powerful pumps, with the necessary boilers, were obtained from Halifax, sent by rail to Annapolis, and then shipped on board a tug, from which they were hoisted into the Ulunda by means of the derricks on the mainmast. These were centrifugal pumps, capable of discharging 2,000 gallons a minute each. One was placed in the engine room, another with its suction in No. 3 hold, and when these two compartments were pumped dry, it was found that in No. 3 hold the leak was easily kept under, while in the engine room there was no leak at all. The third pump was not used. In the two foremost holds 2,000 large casks were then placed, and all the hatches over the leaky holds—Nos. 1, 2, and 4—were battened down, and made airtight with felt, pitch, tow, etc. A small hole was then made in Nos. 1 and 2 hatches, about 2 ft. square. When the tide had sunk its farthest, these two holes were closed and made perfectly airtight, in the same manner as the hatches had been. Before this took place the whole of the lower deck over the badly damaged holds had been prevented from bursting up by means of wooden shores, which were placed in rows about 4 ft. apart, and wedged firmly into position. The wood for the shores was obtained from Annapolis, and the casks from St. John. The ship went ashore on August 26, 1890. This work was commenced on September 8, and completed ten days afterward. The labor of repairing her could only be carried out at low tide, and only then with the greatest difficulty, as the decks were very slippery with weeds, etc., and inclined at an angle of 30 deg. Everything was ready for floating her off at high tide on the 18th, and the hatches were closed up on that day. She was raised off the rocks by the water rising and compressing the air in the two foremost holds, assisted by the buoyancy of the engine room and No. 3 compartments. At high water the bow was afloat, but she was aground by the stern. When, however, she was taken in tow by three tugs, she slowly slid down the reef and floated into deep water. One tug was placed on each bow, and the third was ahead. In this state she was towed into West Port, a distance of four miles, and there beached on a sheltered stretch of sand. The casks performed no part in floating the ship off, but were only there in case the great pressure of air should cause the escape of some of it, in which event all the space underneath the lower deck would soon have been occupied with water instead of air. These casks would then, of course, have served to displace a large amount of this water, and so keep her afloat. Luckily the deck did not leak, and the barrels were thus not instrumental in the raising. When beached the hatches were taken off, the casks removed, and a false deck was built about 7 ft. below the lower deck, and about 10 ft. above the keel. This was used as the bottom of the ship to take her round to Halifax, and was built in the following manner: A kind of iron platform, about 2 ft. wide, runs along the sides of the holds in the Ulunda for strengthening purposes, braced at intervals of 15 ft. by iron beams across the ship. On this was built the wooden deck. Beams for this deck were constructed of three 3 in. planks, and were laid down on the iron platform about 3½ ft. apart, and firmly wedged into the ship's side. On these beams a layer of 3 in. planks was placed in a fore-and-aft direction and nailed down; on this were three layers of felt, and on this again more planks were laid down in the same direction as before. The whole deck was then carefully calked and the sides made watertight with Portland cement. This deck only extended to the engine room bulkhead through the two foremost holds. It was prevented from bursting up by the pressure on the bottom of it, by means of shores, in the same manner as the iron deck had been served before. Shores were, therefore, connecting the three decks—the upper deck, lower deck, and wooden deck—this being done to equalize the pressure on the deck and the two permanent decks, and thus gain additional strength. extemporé No deck was built in either of the after compartments, inasmuch as No. 3 hold was kept clear of water as before by its pump, and in No. 4 the deck was not necessary. To have built one there, as in the two foremost ones, although it would have given a little more reserve of buoyancy to the ship, would have raised the stern higher than the bows, and so would have increased the upward pressure on the wooden deck, and thus have increased the liability to burst up. For the same reason, when raising the ship off the rocks, no compressed air was used in the after hold to lift the ship. The anchors and cables were in both cases transferred aft, for the same purpose, namely, to diminish the upward pressure forward. In the case of the wooden deck leaking, 200 of the same casks were placed between it and the lower deck in the foremost hold to retain some of the buoyancy of the forepart, which would otherwise be lost. No decks were built in the compartment before the collision bulkhead, as very little buoyancy was lost by that space being full of water, and all that was there was confined to that compartment by the bulkhead and the iron lower deck. While all these foregoing arrangements were being made for the exclusion of water from the inside of the ship, the engineers and firemen were employed clearing the engine room of some fifty tons of coal which had been washed from the open bunkers into the machinery by the sea, when the engine room was full and the ship on the reef. The greatest difficulty was experienced in digging out and excavating the engines from the coal and dirt, and still greater was the labor of cleaning all the mechanism and putting everything once more in an efficient steaming condition. But all was finished soon after the decks had been completed, and on October 12 she was ready for sea. On the following day she was floated off and started on her perilous voyage to Halifax, using her own engines, and making about five and a half knots an hour. Her steam pumps were by this time all ready for service to assist the big ones on deck in an emergency. She anchored once on her way round, at Shelburne, on the coast of Nova Scotia, arriving at Halifax at 1 p.m. on October 17. The trip round was a very anxious time for all hands, more especially when they were overtaken by a fresh gale in the Atlantic, for the forward deck was very liable to be burst up with the increased pressure on it caused by the pitching of the ship; also the rudder was entirely unable to bear any strain on it, because the lower part of the rudder post was unconnected with the stern post, part of the stern framing which connects the two having been broken off. Any heavy sea was therefore likely to carry away the rudder altogether, or the same accident might happen if the helm was put down too hard, rendering the ship unmanageable. She was placed in dry dock as soon as she arrived at Halifax, and it was not until then that the full extent of the damages, caused by the pounding on the rocks, could be fully realized. The first 20 feet of the keel had been torn completely out, and about 30 feet from the stern there was an immense hole, with the thick plates torn and bent like paper, the framing and stanchions being twisted into all sorts of shapes almost beyond recognition. Under the foremast the bottom of the ship was bent up in the form of an arch, having been raised 4 feet above its natural position, with an immense hole punctured on the starboard side, besides several smaller ones. Also the aftermost 20 feet of keel was torn and jagged, with several small holes in the skin, and the lower portion of the stern framing was broken off, leaving the rudder post to hang down unsupported at its extremity. It would strike one on looking at these gaping wounds that it would be nearly impossible to place the Ulunda in an efficient condition again, but the work of renewing the damaged plates is being carried out at a great rate, and in three months' time it is hoped that all the repairs necessary will be completed and the ship once more doing her duty. She has already cost her owners some $10,000, and $40,000 are estimated to cover all future repairs. The foremast was snapped off in a somewhat novel manner. She was pivoted on the rocks by her bows, and at high tide, the day after she struck, a breeze sprang up and turned her round; the tide sinking again, the whole weight of the ship came on the bottom of the ship where she was then touching, namely, just on the spot where the foremost was stepped, and right astern, leaving the center portion of the ship unsupported. This caused the foremast to rise, and it being held down by wire rigging, it snapped in several places, at the same time tearing up the shrouds from the deck. This accounts also for the arch-like bulge in the bottom at that spot and for the damages astern; also for the fact that Captain Kelly discovered the ship with her head to sea. Another incident happened when the ship was just rising off the rocks, which nearly resulted in a catastrophe. When the ship was just beginning to lift, the leak in No. 3 compartment was found to be gaining on its pump. A diver was at once sent down to ascertain the cause, and he found that a small hole, about 6 inches square, had been punctured in the skin, which until then had been kept tight by the rock that had caused it. It was necessary to close this leak at once. An iron bolt, which was screwed for a nut at one end, was obtained and passed through a strong piece of wood about 2 feet square. The inside of this board was cushioned with canvas and oakum, and it was taken down outside the ship by the diver and placed over the hole, with the feathered end of the bolt sticking through the hole; the diver was then sent down inside the hold, and with a nut set up the whole cushion until the flow of water was stopped. The leak was thus stopped which had threatened the arrangements for floating the ship with failure. It has been seen that the method of raising the Ulunda was very simple. She was floated off by the rising tide. If there had been only a small instead of an 18 foot rise, some other mode would have to have been adopted. No attempt was made to stop any of the leaks, except the one just stated, but a deck above the lacerations was made water-tight, and this, together with the sides of the ship hanging down, formed a kind of diving bell, the pressure of air in which, caused by the water outside, acting on this deck, being the principal means of buoying up the ship, assisted by the buoyancy of the two water-tight compartments. The deck afterward built was only necessary for the safety of the ship, she being able to float without it; but it would have been suicidal to trust the ship on the Atlantic in the state she was in when raised, since with any swell on, the compressed air would escape and its place be taken by water, the buoyancy necessary for keeping her afloat being thus lost. It only remains to be said that the risks run in steaming around to Halifax by herself were, as it was, very great, and had the wind and sea been less favorable, the undertaking would probably have proved a disastrous failure. About HackerNoon Book Series: We bring you the most important technical, scientific, and insightful public domain books. This book is part of the public domain. Various (2004). Scientific American Supplement, No. 799, April 25, 1891. Urbana, Illinois: Project Gutenberg. Retrieved https://www.gutenberg.org/cache/epub/11649/pg11649-images.html This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at , located at . www.gutenberg.org https://www.gutenberg.org/policy/license.html

THE RAISING OF THE ULUNDA

On the Magnitude of the Object of the War, and the Efforts to be Made

Scientific American Supplement, No. 717, September 28, 1889, by Various, is part of the HackerNoon Books Series. You can jump to any chapter in this book . EXPERIMENTAL AID IN THE DESIGN OF HIGH SPEED STEAMSHIPS. here EXPERIMENTAL AID IN THE DESIGN OF HIGH SPEED STEAMSHIPS. By D. P. The achievement of one triumph after another in the matter of high speed steamships, and especially the confidence with which pledges of certain results are given and accepted long before actual trials are made, form one of the most convincing proofs of the important part which scientific methods play in modern shipbuilding. This is evident in the case of ships embodying novel or hitherto untried features, and more especially so in cases where shipbuilders, having no personal practical experience or data, achieve such results. This was notably illustrated in the case of the Fairfield Co. undertaking some five years ago to build and engine a huge craft of most phenomenal form and proportions, and to propel the vessel at a given speed under conditions which appeared highly impracticable to many engaged in the same profession. The contract was proceeded with, however, and the Czar of Russia's wonderful yacht Livadia was the result, which (however much she may have justified the professional strictures as to form and proportions) entirely answered the designer's anticipations as to speed. Equally remarkable and far more interesting instances are the Inman liners City of Paris and City of New York, in whose design there was sufficient novelty to warrant the degree of misgiving which undoubtedly existed regarding the Messrs. Thomson's ability to attain the speed required. In the case at least of the City of Paris, Messrs. Thomson's intrepidity has been triumphantly justified. An instance still more opposite to our present subject is found in the now renowned Channel steamers Princess Henrietta and Princess Josephine, built by Messrs. Denny, of Dumbarton, for the Belgian government. The speed stipulated for in this case was 20½ knots, and although in one or two previous Channel steamers, built by the Fairfield Co., a like speed had been achieved, still the guaranteeing of this speed by Messrs. Denny was remarkable, in so far as the firm had never produced, or had to do with, any craft faster than 15 or 16 knots. The attainment not only of the speed guaranteed, but of the better part of a knot in excess of that speed, was triumphant testimony to the skill and care brought to bear upon the undertaking. In this case, at least, the result was not one due to a previous course of "trial and error" with actual ships, but was distinctly due to superior practical skill, backed and enhanced by knowledge and use of specialized branches in the science of marine architecture. Messrs. Denny are the only firm of private shipbuilders possessing an experimental tank for recording the speed and resistance of ships by means of miniature reproductions of the actual vessels, and to this fact may safely be ascribed their confidence in guaranteeing, and their success in obtaining, a speed so remarkable in itself and so much in excess of anything they had previously had to do with. Confirmatory evidence of their success with the Belgian steamers is afforded by the fact that they have recently been instructed to build for service between Stranraer and Larne a paddle steamer guaranteed to steam 19 knots, and have had inquiries as to other high speed vessels. In estimating the power required for vessels of unusual types or of abnormal speed, where empirical formulæ do not apply, and where data for previous ships are not available, the system of experimenting with models is the only trustworthy expedient. In the case of the Czar's extraordinary yacht, the Livadia, already referred to, it may be remembered that previous to the work of construction being proceeded with, experiments were made with a small model of the vessel by the late Dr. Tideman, at the government tank at Amsterdam. On the strength of the data so obtained, coupled with the results of trials made with a miniature of the actual vessel on Loch Lomond, those responsible for her stipulated speed were satisfied that it could be attained. The actual results amply justified the reliance placed upon such experiments. The design of many of her Majesty's ships has been altered after trials with their models. This was notably the case in connection with the design of the Medway class of river gunboats. The Admiralty constructors at first determined to make them 110 ft. long, by only 26 ft. in breadth. A doubt arising in their minds, the matter was referred to the late Mr. Froude, who had models made of various breadths, with which he experimented. The results satisfied the Admiralty officers that a substantial gain, rather than a loss, would follow from giving them much greater beam than had been proposed, and this was amply verified in the actual ships. So long ago as the last decade of last century, an extended series of experiments with variously shaped bodies, ships as well as other shapes, were conducted by Colonel Beaufoy, in Greenland dock, London, under the auspices of a society instituted to improve naval architecture at that time. Robert Fulton, of America, David Napier, of Glasgow, and other pioneers of the steamship, are related to have carried out systematic model experiments, although of a rude kind in modern eyes, before entering on some of their ventures. About 1840 Mr. John Scott Russell carried on, on behalf of the British Association, of which he was at that time one of its most distinguished members, an elaborate series of investigations into the form of least resistance in vessels. For this purpose he leased the Virginia House and grounds, a former residence of Rodger Stewart, a famous Greenock shipowner of the early part of the century, the house being used as offices, while in the grounds an experimental tank was erected. In it tests were made of the speed and resistance of the various forms which Mr. Russell's ingenuity evolved—notably those based on the well-known stream line theory—as possible types of the steam fleets of the future. All the data derived from experiment was tabulated, or shown graphically in the form of diagrams, which, doubtless, proved of great interest to the of the British Association of that day. Mr. Russell returned to London in 1844, and the investigations were discontinued. savants It will thus be seen that model experiments had been made by investigators long before the time of the late Dr. William Froude, of Torquay. It was not, however, until this gentleman took the subject of resistance of vessels in hand that designers were enabled to render the results from model trials accurately applicable to vessels of full size. This was principally due to his enunciation and verification by experiment of what is now known as the "law of comparison," or the law by which one is enabled to refer accurately the resistance of a model to one of larger size, or to that of a full sized vessel. In effect, the law is this—for vessels of the same proportional dimensions, or, as designers say, of the same lines, there are speeds appropriate to these vessels, which vary as the square roots of the ratio of their dimensions, and at these appropriate speeds the resistances will vary as the cubes of these dimensions. The fundament upon which the law is based has recently been shown to have found expression in the works of F. Reech, a distinguished French scientist who wrote early in the century. There are no valid grounds for supposing that the discovery of Reech was familiar to Froude; but even were this so, it is abundantly evident that, although never claimed by himself, there are the best of grounds for claiming the law of comparison, as now established, to be an independent discovery of Froude's. Dr. Froude began his investigations with ships' models at the experimental tank at Torquay about 1872, carrying it on uninterruptedly until his death in 1879. Since his decease, the work of investigation has been carried on by his son, Mr. R. E. Froude, who ably assisted his father, and originated much of the existing apparatus. At the beginning of 1886, the whole experimental appliances and effects were removed from Torquay to Haslar, near Portsmouth, where a large tank and more commodious offices have been constructed, with a view to entering more extensively upon the work of experimental investigation. The dimensions of the old tank were 280 ft. in length, 36 ft. in width, and 10 ft. in depth. The new one is about 400 ft. long, 20 ft. wide, and 9 ft. deep. The new establishment is more commodious and better equipped than the old, and although the experiments are taken over a greater length, the operators are enabled to turn out results with as great dispatch as in the Torquay tank. The adjacency of the new tank to the dockyard at Portsmouth enables the Admiralty authorities to make fuller and more frequent use of it than formerly. Since the value of the work carried on for the British government has become appreciated, several experimental establishments of a similar character have been instituted in other countries. The Dutch government in 1874 formed one at Amsterdam which, up till his death in 1883, was under the superintendence of Dr. Tideman, whose labors in this direction were second only to those of the late Dr. Froude. In 1877 the French naval authorities established an experimental tank in the dockyard at Brest, and the Italian government have just completed one on an elaborate scale in the naval dockyard at Spezia. The Spezia tank, which is 500 ft. in length by about 22 ft. in breadth, is fully equipped with all the special and highly ingenious instruments and appliances which the scientific skill of the late Dr. Froude brought into existence, and have been since his day improved upon by his son, Mr. R. E. Froude, and other experts. Through the courtesy of our own Admiralty and of Messrs. Denny, of Dumbarton, the Italians have been permitted to avail themselves of the latest improvements which experience has suggested, and the construction of the special machinery and apparatus required has been executed by firms in this country having previous experience in this connection—Messrs. Kelso & Co., of Commerce Street, Glasgow; and Mr. Robert W. Munro, of London. Having briefly traced the origin and development of the system of model experiment, it may now be of interest to describe the of such experiments, and explain the way in which they are made applicable to actual ships. The models with which experiments are made in those establishments conducted on the lines instituted by Mr. Froude are made of paraffin wax, a material well adapted for the purpose, being easily worked, impervious to water, and yielding a fine smooth surface. Moreover, when done with, the models may be remelted for further use and all parings utilized. They are produced in the following manner: A mould is formed in clay by means of cross sections made somewhat larger than is actually required, this allowance being made to admit of the cutting and paring afterward required to bring the model to the correct point. Into this mould a core is placed, consisting of a light wooden framework covered with calico and coated with a thick solution of clay to make it impervious to the melted paraffin. This latter substance is run into the space between the core and the mould and allowed to cool. This space, forming the thickness of the model, is usually from ¾ in. for a model of 10 ft. long to 1¼ in. and 1½ in. for one of 16 ft. and 18 ft. long. When cold, the model is floated out of the mould by water pressure and placed bottom upward on the bed of a shaping machine, an ingenious piece of mechanism devised by the late Dr. Froude, to aid in reducing the rough casting to the accurate form. The bed of this machine, which travels automatically while the machine is in operation, can be raised or lowered to any desired level by adjusting screws. A plan of water lines of the vessel to be modeled is placed on a tablet geared to the machine, the travel of which is a function of the travel of the bed containing the model. With a pointer, which is connected by a system of levers to the cutting tools, the operator traces out the water lines upon the plan as the machine and its bed are in motion, with the result that corresponding lines are cut upon the model. The cutting tools are swiftly revolving knives which work on vertical spindles moved in a lateral direction (brought near or removed from each other), according to the varying breadth of the water lines throughout the length of the model, as traced out by the operator's pointer. In this way a series of longitudinal incisions are made on the model at different levels corresponding to the water lines of the vessel. The model is now taken from the bed of the machine and the superfluous material or projection between the incisions is removed by means of a spokeshave or other sharp hand tool, and the whole surface brought to the correct form, and made fair and smooth. modus operandi To test accuracy of form, the weight of model is carefully taken, and the displacement at the intended trial draught accurately determined from the plan of lines. The difference between the weight of model and the displacement at the draught intended is then put into the bottom of the model in the form of small bags of shot, and by unique and very delicately constructed instruments for ascertaining the correct draught, the smallest error can at once be detected and allowed for. The models vary in size from about one-tenth to one-thirtieth of the size of the actual ship. A model of the largest size can be produced and its resistance determined at a number of speeds in about two days or so. The mode of procedure in arranging the model for the resistance experiment, after the model is afloat in the tank at the correct draught and trim, consists in attaching to it a skillfully devised dynamometric apparatus secured to a lightly constructed carriage. This carriage traverses a railway which extends the whole length of the tank about 15 in. or 18 in. above the water. The floating model is carefully guided in its passage through the water by a delicate device, keeping it from deviating either to the right or left, but at the same time allowing a free vertical and horizontal motion. The carriage with the model attached is propelled by means of an endless steel wire rope, passing at each end of the tank around a drum, driven by a small stationary engine, fitted with a very sensitive governor, capable of being so adjusted that any required speed may be given to the carriage and model. The resistance which the model encounters in its passage through the water is communicated to a spiral spring, and the extension this spring undergoes is a measure of the model's resistance. The amount of the extension is recorded on a revolving cylinder to a much enlarged scale through the medium of levers or bell cranks supported by steel knife edges resting on rocking pieces. On the same cylinder are registered "time" and "distance" diagrams, by means of which a correct measure of the speed is obtained. The time diagram is recorded by means of a clock attached to an electric circuit, making contact every half second, and actuating a pen which forms an indent in what would otherwise be a straight line on the paper. The distance pen, by a similar arrangement, traces another line on the cylinder in which are indents corresponding to fixed distances of travel along the tank, the indents being caused by small projections which strike a trigger at the bottom of the carriage as it passes, and make electric contact. From these time and distance diagrams accurate account can be taken of the speed at which the model and its supporting carriage have been driven. Thus on the same cylinder is recorded graphically the speed and resistance of the model. The carriage may be driven at any assigned speed by adjusting the governor of the driving engine already alluded to, but the record of the speed by means of the time and distance diagrams is more definite. When the resistances of the model have been obtained at several speeds, varying in some cases from 50 to 1,000 feet per minute, the speeds are set off in suitable units along a base line, and for every speed at which resistance is measured, the resistance is set off to scale as an ordinate value at those speeds. A line passing through these spots forms the "curve of resistance," from which the resistance experienced by the model at the given trial speeds or any intermediate speed can be ascertained. The resistance being known, the power required to overcome resistance and drive the actual ship at any given speed is easily deduced by applying the rule before described as the law of comparison.— The Steamship. About HackerNoon Book Series: We bring you the most important technical, scientific, and insightful public domain books. This book is part of the public domain. Various (2006). Scientific American Supplement, No. 717, September 28, 1889. Urbana, Illinois: Project Gutenberg. Retrieved https://www.gutenberg.org/cache/epub/17755/pg17755-images.html This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at , located at . www.gutenberg.org https://www.gutenberg.org/policy/license.html

EXPERIMENTAL AID IN THE DESIGN OF HIGH SPEED STEAMSHIPS

GATHERING CLOUDS.

Now—soft awhile—have I arrived so near the end?

These events occupied so much time, that June had numbered more than half its days

We held a council, to decide on our future movements

Our escort had been directed to prepare our abode for the night at the inn

Mark Twain's Speeches by Mark Twain, is part of the HackerNoon Books Series. You can jump to any chapter in this book . AN UNDELIVERED SPEECH here AN UNDELIVERED SPEECH The steamship St. Paul was to have been launched from Cramp’s
          shipyard in Philadelphia on March 25, 1895.  After the
          launching a luncheon was to have been given, at which Mr.
          Clemens was to make a speech.  Just before the final word was
          given a reporter asked Mr. Clemens for a copy of his speech to
          be delivered at the luncheon.  To facilitate the work of the
          reporter he loaned him a typewritten copy of the speech.  It
          happened, however, that when the blocks were knocked away the
          big ship refused to budge, and no amount of labor could move
          her an inch.  She had stuck fast upon the ways.  As a result,
          the launching was postponed for a week or two; but in the mean
          time Mr. Clemens had gone to Europe.  Years after a reporter
          called on Mr. Clemens and submitted the manuscript of the
          speech, which was as follows: Day after to-morrow I sail for England in a ship of this line, the Paris. It will be my fourteenth crossing in three years and a half. Therefore, my presence here, as you see, is quite natural, quite commercial. I am interested in ships. They interest me more now than hotels do. When a new ship is launched I feel a desire to go and see if she will be good quarters for me to live in, particularly if she belongs to this line, for it is by this line that I have done most of my ferrying. People wonder why I go so much. Well, I go partly for my health, partly to familiarize myself with the road. I have gone over the same road so many times now that I know all the whales that belong along the route, and latterly it is an embarrassment to me to meet them, for they do not look glad to see me, but annoyed, and they seem to say: “Here is this old derelict again.” Earlier in life this would have pained me and made me ashamed, but I am older now, and when I am behaving myself, and doing right, I do not care for a whale’s opinion about me. When we are young we generally estimate an opinion by the size of the person that holds it, but later we find that that is an uncertain rule, for we realize that there are times when a hornet’s opinion disturbs us more than an emperor’s. I do not mean that I care nothing at all for a whale’s opinion, for that would be going to too great a length. Of course, it is better to have the good opinion of a whale than his disapproval; but my position is that if you cannot have a whale’s good opinion, except at some sacrifice of principle or personal dignity, it is better to try to live without it. That is my idea about whales. Yes, I have gone over that same route so often that I know my way without a compass, just by the waves. I know all the large waves and a good many of the small ones. Also the sunsets. I know every sunset and where it belongs just by its color. Necessarily, then, I do not make the passage now for scenery. That is all gone by. What I prize most is safety, and in the second place swift transit and handiness. These are best furnished, by the American line, whose watertight compartments have no passage through them; no doors to be left open, and consequently no way for water to get from one of them to another in time of collision. If you nullify the peril which collisions threaten you with, you nullify the only very serious peril which attends voyages in the great liners of our day, and makes voyaging safer than staying at home. When the Paris was half-torn to pieces some years ago, enough of the Atlantic ebbed and flowed through one end of her, during her long agony, to sink the fleets of the world if distributed among them; but she floated in perfect safety, and no life was lost. In time of collision the rock of Gibraltar is not safer than the Paris and other great ships of this line. This seems to be the only great line in the world that takes a passenger from metropolis to metropolis without the intervention of tugs and barges or bridges—takes him through without breaking bulk, so to speak. On the English side he lands at a dock; on the dock a special train is waiting; in an hour and three-quarters he is in London. Nothing could be handier. If your journey were from a sand-pit on our side to a lighthouse on the other, you could make it quicker by other lines, but that is not the case. The journey is from the city of New York to the city of London, and no line can do that journey quicker than this one, nor anywhere near as conveniently and handily. And when the passenger lands on our side he lands on the American side of the river, not in the provinces. As a very learned man said on the last voyage (he is head quartermaster of the New York land garboard streak of the middle watch), “When we land a passenger on the American side there’s nothing betwix him and his hotel but hell and the hackman.” I am glad, with you and the nation, to welcome the new ship. She is another pride, another consolation, for a great country whose mighty fleets have all vanished, and which has almost forgotten what it is to fly its flag to sea. I am not sure as to which St. Paul she is named for. Some think it is the one that is on the upper Mississippi, but the head quartermaster told me it was the one that killed Goliath. But it is not important. No matter which it is, let us give her hearty welcome and godspeed. About HackerNoon Book Series: We bring you the most important technical, scientific, and insightful public domain books. This book is part of the public domain. Mark Twain (2004). Mark Twain's Speeches. Urbana, Illinois: Project Gutenberg. Retrieved October 2022 https://www.gutenberg.org/cache/epub/3188/pg3188-images.html This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at , located at . www.gutenberg.org https://www.gutenberg.org/policy/license.html

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