My first book on space was by Maxwell Hunter. In THRUST INTO SPACE used feet per second. He gave one set of numbers that was very simple and very useful. 52 minutes at 1G equals 100,000 feet per second. When you start to design you need a starting number these were a good start. The next simple number needed would be what is the bottom line for efficiency usually in pounds of thrust per pound of propellant. The number I wanted 8000; I end up settling for 2000 overall.
The A.I.A.A. American Institute of Aeronautics and Astronautics put out one of the books I had on design of rockets. They used pounds per cubic inch for the weight of metals. The numbers they used for comparison were only to 2 or 3 places or about 2.8 for steel and 1.0 for aluminum depending on the alloy. It was a very good book, on my web pages I discuss the book more in depth. I do not know the name as I never cared about the title as I did not plan to write about any of this. I recently saw a couple of books from that series and recognized the covers.
Space is where I always wanted to be
Just off harmlessly putting along. That is all one can really do.