This section is from the book "American Plumbing Practice", by The Engineering Record. Also available from Amazon: Plumbing: A working manual of American plumbing practice.
In the governor's house of the Home for Volunteer Soldiers, at Hampton, Va., it was desired to provide heating capacity for the large kitchen boiler B, in addition to that furnished by the ordinary water-back D of the adjacent range A.
This was effected by connecting the boiler circulation pipes F and G with a steam water-back S, which received steam from the house-heating apparatus through pipe E and returned it through R. The steam water-back S consists simply of an iron case L containing a steam coil M. This is surrounded by water admitted at the bottom through the branch J from the cold circulation pipe G. After being heated it flows out through branch I into the hot circulation pipe of kitchen boiler B.
This arrangement was made by Bartlett & Hay-ward, of Baltimore Md., and is said to operate satisfactorily, heating a large quantity of water rapidly with both water-backs together, and working well with either alone.