From a large collection of glass stereoviews that belonged to Dr William Gardiner Anglin (1856 - 1934) who lectured at Queens University in Kingston, Ont.
A French 75mm Field Gun circa 1905, the 75mm entered service with the French Army in 1898 and is regarded as the world's first modern artillery piece.
I'm not sure what is happening with the gun in the photograph, the recoil mechanism appears to be disconnected with the barrel in the fully retracted position and the breach block is missing.