Most interesting chapter from a book entitled "Railway Employees' Book of Ready Reference" by Thomas A. Annis, published in 1904 by George B. M. Seager, Adrian, Michigan.
The book is primarily about air brake and steam locomotive systems. It contains some excellent hand-drawn cutaway diagrams of machine components, and a lot of questions and answers about machinery, all designed to familiarize the railroad mechanic with the systems that were in use at the time. But it also had this chapter beginning on page 124, which I have typed out in full. Spelling, capitalization, punctuation, and phrasing are unchanged from the original. The Metric System of Weights and Measures. ------------------------------------------ History of the Meter. ------------------------------------------ Present Status of the Metric System. For many years the advocates of the metric system of weights and measures have been laboring unceasingly to have the United States government adopt this system, and make it the only legal one in this country. As this is a subject of vital importance to every manufacturer and railroad company and very interesting to mechanics, we will endeavor to briefly explain what is meant by the metric system: This system of weights and measure was designed to remove the confusion arising out of the excessive diversity of weights and measures prevailing throughout the world, by substituting in the place of the arbitrary and inconsistent system, actually in use, a simple one, constructed on scientific principles and resting upon an invariable standard. The system has been successfully adopted by more than one-half of the civilized world, which includes the following countries: Holland, Belgium, Spain, Portugal, Italy, the German Empire, Greece, Roumania, British India, Mexico, New Grenada, Ecuador, Peru. Switzerland, without adopting the system in full has done the same for her standard of weights; Austria has adopted the system for custom house purposes, and Turkey has introduced a metric measure of length; in Great Britain the use of metric denominations in business transactions has been made legally permissible, and now a committee of the house of commons has recommended that within two years the metric system of weights and measures shall be rendered compulsory in the British Isles; in the United States metric weights and measures were legalized by an act of congress passed July 27, 1866; and now the house committee on coinage, weights and measures recommended that the metric system be adopted by the various departments of the government July 1, 1898, and by the nation at large January 1, 1901. It is therefore fair to presume that within a few years this system will be the only legal one used in this country, so it will be well for every mechanic to study and familiarize himself with the table of metric threads, shown on page 126, which were adopted by the German engineers. We do not think a better table could be given. A French meter equals 39.37 inches in length. A decimeter equals 3.937 inches in length. A centimeter equals 0.3937 inches in length. A millimeter equals 0.03937 inches in length. We would no doubt profit by adopting this systems of weights and measures (measures of capacity), as much confusion exists in the various states having different standards. While the metric system measures of capacity divides by tenths like its linear measurements because it does not divide evenly like the metric system.* For example, one rode contains 16 1-2 feet and one mile 5,280 feet, but when the effort is made to substitute the French meter for our inch the difficulties in the way of carrying out the change will become apparent. No objections exist to the meter as a unit of measurement, except that the parts of our existing system cannot be represented in divisions of the meter without the use of numerous figures, which would cause endless confusion. Our standards have been built up and adopted by railroads and manufacturers at a cost of millions of dollars. Perhaps the most important and expensive are our screw threads, and it would be almost impossible to express the number of our threads to any part of the meter without changing the pitch of the threads, which would entail an enormous expense. Manufacturers who have a large foreign trade might profit by the change but an overwhelming majority of the manufacturers and railroads would be forced into an unnecessary expense. The most enthusiastic advocates of this system in this country are theorists who do not realize at what cost a change of measurement could be effected. However, their efforts have been remarkably successful and the change seems inevitable. Machines are now manufactured and used in this country which are geared to cut both United States standard and metric threads. [Following this article was a "Table of Metric Threads" which gave the screw diameter and the thread pitch, both in millimeters, beginning at 1.0 mm diameter and 0.25 mm pitch, ending at 40 mm diameter and 4.4 mm pitch. And yes they used leading zeros before the decimal point throughout.] [end of chapter] *This somewhat convoluted sentence is set forth exactly as written. I think something got left out in the typesetting, most likely something like "While the metric system measures of capacity divides by tenths like its linear measurements the system in use in the United States today does not do so because it does not divide evenly like the metric system." Most interesting, this viewpoint from over a century ago. Their biggest worry was all the existing bolts and threads used in the locomotive and air brake machinery of the time, and the cost of converting all of that legacy machinery to metric measure. But the author was convinced that conversion to metric was not only inevitable in the USA but was also going to happen pretty much immediately. Wasn't there some measure in Congress to do so around that time that failed by just one lousy vote? Carleton
