The cover shown above is an example of hotel advertising used on the WLS-12 E3 variety, mailed with a Montreal Flag cancel dated November 9, 1900, to Afton New York, USA, with an Afton receiving cancel shown below on the reverse.
Below, a copy of the Hotel Carslake letterhead enclosed in the cover above.
In his article on J.C. Wilson patriotics, Gates refers to “The Queen” design as “the only one used by a hotel for advertising”. He illustrates this with his copy of The Queen used by Hotel Carslake, (page 121 of his article), on an E-3 variety, shown below.
This cover has been postally used from Montreal to Maine, and bears a pair of 1¢ QV Numeral stamps postmarked with an Island Pond & Montreal RPO cancellation (serial number 21 with a rarity factor of 50, according to T.P.G. Shaw’s The Handbook and Catalogue of Canadian Transportation Postmarks), dated October 12, 1901.
The cover below is another example of a Hotel Carslake advertising cover, however the four ½¢ Queen Victoria Numeral stamps used to post the envelope to Scotland obscure most of the text. The full text reads “If not delivered in Ten Days, return to, Hotel Carslake, 571, 573, 575 St. James Street, Montreal, Geo. Carslake & Co., Proprietors”. The cover was sold in Maresch auction 435, June 17, 2008.
In his article "Canadian Illustrated Covers" in BNA Topics, E. L. Piggott also shows an image of “The Queen” cover used by Montreal’s Hotel Carslake for advertising. Another copy was sold by auction by Jim Hennok in June 1994 from the collection of Dr. Alan Selby postmarked Kingston September 7, 1900. A copy addressed to Toronto was sold at a Maresch auction February 5, 1998 for $400.