Smithsonian Report, 1910. — Beyer. 



Plate 2. 



1. Gauge Glass for Indicating Height 

 OF Water in a Boiler. Semicircular 

 Steel Guard Shown in Its Normal 

 Position. 



2. When Steam is Turned into a New 

 Gauge Glass the Guard is Revolved 

 to the Front, to Prevent Injury in 

 Case the Glass should Burst. 



3. View of Rope Drive for Rod Mill, Showing Steel Plate Inclosure. 



