Clue number two....
Of course this is India, the other boundary to our region. This is a super set, and it does remind me a lot of vintage postcards.
However I have to wonder how many railway collectors are aware of the amazing reverse to this card ? I have had a little look round (and wait to be corrected by proper Railway historians) but I think this may show the Parsik Tunnel. This started to be constructed in 1906 and was opened in 1916, so it would have been nearing the end when these cards were issued, and would definitely have been a topic of conversation.
In RB.21, our British-American Tobacco Company booklet, published in 1952, this set is listed in the index under B.A.T. Brand Issues as :
20. "Railway" Cigarettes. Cards issued in India, inscribed with B.A.T. or Imperial Tobacco Co. of India names, or both. The sets cited are this one, as "Indian Historical Views (1915), two numbering arrangements - [see] 503", plus three types of "Nautch Girl Series", black and white, coloured, and coloured with playing card inset.
Now the actual listing under 503 is very lengthy, so here it is, scanned :
Our World Tobacco Issues Index tells us that the B.A.T. version of this set was circulating in India in about 1907. However the only set which appears in this section is the Nautch Girls. However that section, to its credit, does also tell you to "See also under Imperial Tobacco Co. of India" - and when you do it not only lists this set, but also explains that the company was "Formed about 1908 to take over B.A.T. interests in India." So obviously at that time the cards were reprinted to add the Imperial Tobacco wording.
The set is described as simply "INDIAN HISTORICAL VIEWS. Sm. 63 x 36. Nd.(25), Two numbering arrangements. See RB.21/503." And it is slightly altered in our updated World Tobacco Issues Index, to : "INDIAN HISTORICAL VIEWS. Sm. 63 x 36. Backs in grey, with "Railway Cigarettes" packet. Nd.(25), Two numbering arrangements. See RB.21/503.