Euan Cameron replied, giving more details about the loco in this photo:
"This is one of sixteen 0-6-0 locos from
Robert Stephenson & Co. delivered to the North British Railway between
1862 and 1864. They arrived during the superintendency of William
Hurst, as one of your correspondents suggested.
They had approximately 5' 0" diameter wheels
at the unusual spacing of 7' 1" + 6' 8". They had deeply slotted
mainframes, with a long front overhang (5’ 3” to the rear of the front
bufferbeam); to the rear of the trailing axle the mainframes were quite
short, at 2’ 10½” (estimated).
The cylinders were 15½” x 24” with vertical
slide valves between the bores. The solid splashers had a thin line
of brass beading on the outer edge.
The boilers had a raised firebox with a large
circular cover on the crown, on which the whistle and steam keys were set,
similar to the pattern later used by Matthew Holmes.
The domes on the middle of the boiler barrel
had brass covers with bell-mouthed open tops. Tall chimneys tapered
inwards towards the top and had broad copper caps.
The weatherboard was a flat vertical sheet
with a small raised curved area, on which the pressure gauge was fitted."
"The photo on your website is believed to show
No. 169 after it was renumbered 864 around 1895. It was Stephenson's
Works no. 1462, built December 1862.
was renumbered 169A in 1886 and 864 in the general renumbering of
duplicate engines in 1895. It was withdrawn a few years later,
Date of Photo
"If the details associated with another print
of this photo in my collection are correct, then this picture can be dated
fairly precisely to the mid-1890s.
The locomotive is near the end of its working
existence and has been barely altered at all, except that the original
bell-mouthed brass dome first fitted has been replaced with one of Thomas
Wheatley's design, and the chimney is of the stovepipe variety also
favoured by Wheatley."
Euan Cameron, New York, New York, USA: January 1, 2012