The 1B49 is a triggered spark gap. Two or more are used in series and the reference 1B29 below gives details of the type of circuit these modulators are used in.
The cathode connection is at the top and the smaller anode connection is at the base.
In addition to the Westinghouse name there is also the General Electric name. The ink is in different colours indicating a later overprinting - probably of the GE name.
The cathode connection and evacuation tube.
The anode has a much smaller diameter.
The wide glass tube envelope is 57 mm in diameter, and including the base is 129 mm tall.
References: Data-sheet, & 1B29. Type 1B49 was first introduced in 1945.
Updated June 22, 2021.