Mountain gunners

[RobL]

Picked up this nice postcard on eBay showing a mule carrying a mountain gun and two men - the men don't appear to be wearing the Royal Artillery cap badge - i'll have to check my sources but the axle tree reminds me more of the earlier 10 pounder mountain gun than the 2.75 inch gun/3.7 inch howitzer later used. Would appreciate any thoughts regarding time, place, unit, equipment etc etc (evidently somewhere hot!)