A question for the forum nerds- "Train Resistance Computer" from 1894?

Train resistance is the resistance to movement; factors such as friction, weight, and aerodynamic drag affect the train's ability to move. Railroads needed this information to determine how much horsepower and time a train would need to move it from point A to B.

I found an old FRA report about train resistance here, but the report does not mention any research into train resistance prior to 1906.

Best guess the slide rule was an early tool to determine if a train had sufficient power to move.

-John

@AcelaNYP posted:

Train resistance is the resistance to movement; factors such as friction, weight, and aerodynamic drag affect the train's ability to move. Railroads needed this information to determine how much horsepower and time a train would need to move it from point A to B.

I found an old FRA report about train resistance here, but the report does not mention any research into train resistance prior to 1906.

Best guess the slide rule was an early tool to determine if a train had sufficient power to move.

-John

You beat me to the punch. I too think the item he is speaking about was an early version.

The topic of train resistance goes back to a couple of research papers published in the UK and New Zealand back in 1871. Then in 1879, U.S. newspapers reported the invention  of the Dynagraph which, carried on a train, ingeniously measured 14 parameters to include some contributing to train resistance. 

From the 18 October 1879 issue of the National Republican:

"This subject of train resistance is one of great importance in the working of railroads successfully, and with the demand of the times for low rates upon local and through freight, is worthy the attention of all our railroad officials."

Here is a link to information about the Cox device from National Museum of American History (part of Smithsonian on the Mall in D.C.).

https://americanhistory.si.edu...lections/nmah_905342

A reprint of Volume 10 (1897) of Locomotive Engineering, which carried this ad, is available on Amazon from Forgotten books, but I'm not sure it contains any more information.  However, the purpose of the circular calculator from Cox is clearly explained in the ad.

In the days before computers, specialized slide rules were sometimes developed to solve specific practical problems. Frederick Taylor, the "Father of Scientific Management," made a great study of machining, which he called the art of cutting metals, and developed a set of slide rules to solve for optimum feeds and speeds given 14 (IIRC) variables found to affect the answer.

That's very interesting information about Frederick Taylor and the slide rules he developed -- what were the 14 variables? I can think of several related to the type of metal being cutting and the kind of cutting tool used, but I don't think I can come up with 14.

Taylor's 1906 Art of Cutting Metals is available online. The 3 questions each machinist needs to answer are what tool, speed, and feed? The slide rules account for 12 (not 14) variables as shown in this screenshot:

Taylor noted he was focused on roughing work done most efficiently, not finish work where the surface finish was important.

IIRC he said that the highest machining productivity was achieved when the tool needed to be be reground after 20 minutes.

Thanks to all for the input, the information was passed along.