Glass negatives, 9 x 12 cm, found at a second hand store in Manitou Beach, near Watrous, Saskatchewan, in 2015. Photos appear to be from an event or series of events that took place in Europe. The aircraft is an Armstrong Whitworth Argosy, a British three-engine biplane passenger airliner used by Imperial Airways from 1926 to 1935, among other carriers. Imperial Airways flew regularly between London and Paris, so perhaps the images were taken in England or France. So, how did they end up in Manitou Beach? Who doesn't love a mystery!
This aircraft is Armstrong Whitworth A.W.154 Argosy Mk. II. G-AAEJ named "City of Coventry". The Mk. II was introduced in 1929, powered by three 420 hp Armstrong Siddeley Jaguar IVA radial piston engines. A total of four of these aircraft were constructed, in service until 1936 (Imperial Airways merged into British Airways in 1935). That aircraft - the one with that registration - flew exclusively on the London-Paris run.
Of the cameras available at the time, the Voigtlander Avus 9x12 folding plate-film camera, marketed from 1919 to 1934, would have been sufficiently portable to be used for these photos. Working with glass negatives would not have been a spur-of-the-moment "snapshot" activity!