The Keystone Gas Balloon Inflation Series

A Keystone sequence of views a of a gas balloon inflating... Negative numbers 12138 to 12150.  Number stamped on the cards indicate that they may have been published on their own, and as part of a larger set. The ones I have are blank on the back. The text on each card indicates a familiarity with ballooning, and the sequence brings out many of the main points in inflating a balloon with Town Gas. Waldsmith describes the balloon as a 'large U.S. Signal Corps gas balloon c. 1905, and  says that the negatives were amongst those acquired from Underwood and Underwood.  This is confirmed by the Library of Congress entry describing the series as U.S. Signal Corps at work on balloon, Ft. Myer, Va., 1907 and showing that there are many more images in the original series (go to http://lcweb2.loc.gov/pp/cphquery.html and search for 'balloon stereo' for further information) The Library of Congress only has copies of half of the stereocards, which is a bit of a tragedy really, as they've lost an entire dimension :*(. 

First, the Keystone Stereoviews

Left: 12138 'Attaching the long silk tube leading from the gas main to neck of the balloon'

Right: 12142 'Attaching the valve to the top of the balloon.'  

Right: 12147 'The nearly filled balloon and method of attaching ballast bags to net.' 

Right:12150 'Attaching the basket weighted with sand-bags to the ring.'

Right:U&U view I haven't seen as a Keystone stereoview.

Right:U&U view matching KS12147.