I found a similar book on railway engineering from 1928. I'll post separately a scan of the title page and of a text page. The forum is giving me errors when I try to upload the images as attachments.
This book isn't written by an MIT professor, but as an alumnus myself, I know that MIT isn't the best place to learn practical civil engineering. It describes the same survey team as Cam's book along with tools needed by the party and the duties of each member.
I looked into the question of horizontal vs. actual length for grade calculation, thinking it might be easier to calculate the track length. We're looking here at right triangles with a base of 100 and height being the % grade. Here are the nubers for the hypotenuse of the triangle for various grades.
| Height | 0 | 0.5 | 1 | 1.5 | 2 | 2.5 | 3 |
| Length | 100.000 | 100.001 | 100.005 | 100.011 | 100.020 | 100.031 | 100.045 |
Note that for a 2% grade, the difference is only a quarter inch. That's one foot in a mile, which is insignificant for railway location.
You might think it difficult to put enough tension on a 100 foot tape to hold it exactly horizontal. There is about half a page in the book about using "broken chains" in such situations - see the attached image.
The reason the word "chain" is used is that in the time before invention of the tape measure, surveying was done with 100 foot chains.
