Green’s Dictionary of Slang

1. a Ganges boatman.

1843		Bellew Memoirs of a Griffin II 64: The dandies, or boatmen, now drew on board the seree, or plank connecting us with the shore.
1864, 1867, 1870		Hotten Sl. Dict.
1879		H. Hartigan Stray Leaves (2nd ser.) 262: [T]he dandis, as the boatmen of the craft containing the fleet were called.
1886		Yule & Burnell Hobson-Jobson (1996) 296: dandy, s. A boatman. The term is peculiar to the Ganges rivers.

2. ‘a kind of vehicle used in the Himalaya, consisting of a strong cloth slung like a hammock to a bamboo staff, and carried by two (or more) men [dandy-wallahs]’ (Y&B).

1880		Times of India 3 Nov. 3/3: As [Missy Baba] is carried up the hill in her dandy, her own particular batman is lost in the crowd [...] but other soldier servants will win the honeyed nothings of her speech.
1881		Times of India 6 July 2/4: [H]e made the natives carry him in a dandy, and completed the journey to the borders of Chinese Thibet, and thence along the whole line of the Western Himalayas.
1884		Civil & Milit. Gaz.27 Mar. (Lahore) 27 Mar. 3/2: [of Simla] [J]ampanis snorting up a hill under the weight of dandis.
1892		Civil & Milit. Gaz. (Lahore) 8 June 3/4: When I want opened my eyes, we had stopped at the foot of our hill, up which we were safely carried in dandies.
1906		Civil & Milit. Gaz. (Lahore) 9 May 9/4: [advert] THE MUSSOORIE TRANSPORT AGENCY, Rajpore. (Opp P. O.) Tongas, Dandies, Ponies, Coolies, Refreshments, Accommodation, at moderate rates.
1910		Civil & Milit. Gaz. (Lahore) 24 July 8/1: The narrow picturesque road [...] seemed to be one long queue of dandies, ponies and peclestrians.