Resource Type

Telephone Attachment. (open access)

Telephone Attachment.

Patent for a telephone attachment for multi-party lines, which allows the user to hold the line against eavesdropping by other users on the line and let multiple people use the line at the same time.
Date: November 23, 1909
Creator: Mitchell, Charles B.
System: The Portal to Texas History
Carbid-Feed Device for Acetylene-Gas Generators. (open access)

Carbid-Feed Device for Acetylene-Gas Generators.

Patent for a carbide-feed device for Acetylene gas generators, which prevents moisture from getting into the carbide and causing it to stick to the walls of the feed tube.
Date: October 19, 1909
Creator: Weaver, John W.
System: The Portal to Texas History