Involuting Drawing Instrument (open access)

Involuting Drawing Instrument

Patent for drawing instrument intended for drawing involuting curves. Includes illustration and instructions.
Date: August 11, 1914
Creator: McCaskill, Oscar E.
System: The Portal to Texas History
Silo. (open access)

Silo.

Patent for a new silo design made of hollow tiles "to provide dead-air spaces within the tile, for the purpose of preventing the rapid passing of heat or cold through the tile" (lines 13-16) including instructions and illustrations.
Date: August 11, 1914
Creator: Sellors, Edward M.
System: The Portal to Texas History