Thanks to Frank "Steamhead" Wilsey for finding and sharing these pages from Heating By Steam and Water: A Practical Treatise on House Heating, published in 1907. He tells us, "This is the earliest orifice system, patented sometime prior to 1901 by Frederic Tudor. Also known as the French or German system since it was popular there. We've seen four of these in Baltimore." And thanks to Gerry Gill for providing us with Mr. Tudor's patents.
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...