Resource Type

Automatic Electric Alarm. (open access)

Automatic Electric Alarm.

Patent for an automatic electric alarm meant to be hooked up to an automatic dry-pipe sprinkler system, and protects against fire. The alarm goes off when the air in the sprinkler pipes falls below a predetermined level. This invention also signals an alert when there is a leak in the pipes, and is an improvement on the circuit-wires for similar alarms.
Date: January 7, 1896
Creator: Williams, George Bayley
System: The Portal to Texas History
Automatic Firing Device for Explosive Shells. (open access)

Automatic Firing Device for Explosive Shells.

Patent for automatic firing device where "an explosive shell may be caused to travel any distance within the range of the shell through the air without exploding" (lines 14-17).
Date: January 7, 1919
Creator: McCombs, Orville K.
System: The Portal to Texas History
Attachment for Adding Machine (open access)

Attachment for Adding Machine

Patent for new and useful improvements in attachments for adding machines which both add and list the sums accumulated by the adding machine.
Date: January 7, 1919
Creator: Walker, Jack L.
System: The Portal to Texas History