Scalloped bottom version -
oval top, round top and rectangular top
Angled base version -
oval top, round top and shield top
This last version is slightly shorter than the others and is made of of a thicker plastic. To the best of my knowledge they were exclusively used in Canada.
As the month progresses I will be going alphabetically through the known examples, listing some sales info and company brochures featuring the thermometers, provide a list of those that are waiting to be found and wrap up with some interesting non gas examples as these were used for all types of advertising. They are an interesting collectible because examples can be found for most of the companies we collect, they don't take up a lot of room, and they are usually fairly inexpensive. Note I said "usually". As we go through the known examples feel free to post when that letter is being listed or email photo to me for posting if you miss out on a letter or don't wish to post youself. I will began with examples starting with "A" tomorrow.
[This message has been edited by wfort39663 (edited 11-13-2007).]