Original photo caption reads: "Elevation of boiler backhead showing (left to right at top) steam pressure gauge, sight glass (indicates water level in boiler), manhole (for maintenance access to steam space), and try-cocks (used to determine water level if sight glass is inoperative). Below the firedoors lie air plenums which supply air from blower to firegrates; plenum door at lower left has been removed for photography. Each boiler was built by W. & A. Fletcher Co. to operate at 50 p.s.i. - Ferry TICONDEROGA, Route 7, Shelburne, Chittenden County, VT".