Unfortunately we don't have a source for this article called "It's All in the Venting" by John Schulz, but it's probably one of the best articles we've ever read on air venting from steam systems. It helped Dan Holohan understand a lot when he was writing The Lost Art of Steam Heating.
The Improved Webster Type "R" System of Steam Heating is a service bulletin from Warren Webster and Company (The Pioneers of Vacuum Steam Heating), established in 1888.
This manual was created by O-E Specialty Manufacturing Co. and outlines how to install the "O-E" Perfect System, which is a Vapor Vacuum heating system.
Here is the original Installation and Operating Instructions and Parts List for The H.B. Smith Company's Oil Fired Cast Iron Hot Water Boilers (No. OHB-13W). This is esti...