These get called "shot glasses" and "tumblers". But "double shot" is the more technicaly accurate term going by early glass house cataloge descriptions. 2 shots of booze and a couple cubes is what they had in mind. They run about 3" x 3" and have mug bases of various numbers of panels. Its a classic design of glass and examples can be found blown and cut from the late 1700s to machine made ones that are still being produced. The RR ones were popular from the last quarter of the 1800's to just into the machine made age. The name of the railroad is embossed backwards on the base but can be read in the bottom of the glass when empty. On the hand made ones the base rim will show evidence of a 'touch" pontil mark or be polished smooth. The examples here are, Philadelpia & Reading, New York, Lake Erie & Western, and Baltimore & Ohio. There are many more railroads that used these glasses as well as the Pullman Car Co. Amber & green colors can be found.