The only Westinghouse Stopper Lamps seen by this writer have had bulbous envelopes. A lamp with a different shaped envelope is mentioned here for the benefit of those web site viewers who also have that experience. A Letter to the Editor appeared in the Electrical World on Nov 21, 1914 (Vol 64, No 21, pg 1012) in which a photograph was shown of a Stopper Lamp with a tubular envelope as well as the bulbous one. A scanned picture of that photograph is given below.