STC 24B9 Trigatron. 6" high x 2½" dia.
This gasfilled tube is normally covered in a protective 'sock' made from what looks like resin-impregnated bandage (as in right-hand picture), to prevent injury if the very thick glass shatters.
These devices were typically used as pulse modulators for high-power radar applications.
The table below lists specs for two other devices from the 1959 Ediswan catalogue.
< Small ¾" dia. gas-filled gap tube, possibly argon or xenon as it glows blue-white when a high voltage is applied.
Marked V1507 10E/462
This unusual device has a very small needle gap in the round cavity at the bottom, visible through small glass windows either side. The gap is adjustable via a screw arrangement on the right, sealed with a cylindrical metal bellows arrangement. The bottom cavity is made of solid copper, 10mm thick - it's not clear whether this heavy construction is for thermal, mechanical or electrical (RF?) reasons. Judging from the comments below, maybe it was designed to bolt in-line to flanges of a waveguide.
Thanks to Harry Visser for the following info : The 1B26 is a spark gap tube. It is used between the ring duplexer and the receiver section in a RADAR set. It is designed to keep the RF out of the receiver section. A ring duplexer is pretty good at isolation but not enough to prevent blowing the mixer diodes in the receiver. The terminal is used with some high voltage to make the tube more sensitive. My MG2 Hughes RADAR has one.
I've also received the following info from Manuel Carbonell: 1B26: Information from
the book "Microwave Duplexers", Massachusetts Institute of Technology, Radiation
Laboratory Series, McGraww-Hill
The krytron is a high speed, high current gas filled tube. This tube can switch thousands of amps at thousands of volts. It is similar to a thyratron except that it is a 4 terminal device. The fourth terminal is a "keep alive" electrode that maintains a glow discharge in the tube at all times. This make the tube much faster and the timing more uniform. There is also a small amount of radioactive Nickel in the tube. The ionization helps further stabilize the propagation delay.
The krytron was used on the early atomic bombs (and on other mundane applications like copy machine flash triggers) Next to this krytron is a hunk of "Trinitite", the green fused sand from under ground zero of the first atomic bomb test at Alamagordo, New Mexico. Still just a tiny bit radioactive.
Thanks to Neon John for this info.
Telefunken sparkgap tube