Physical description
Air Gauge - duplex type for tramcars with self lapping brakes - brass case, and back, with two needles - red and black - glass front, paper pressure indication. The red needle shows the pressure in the air-tank and the black needle, the pressure in the brake cylinder. Note the red needle is on the wrong side of the stop, possibly due to transport.
Would have been used on a Melbourne or MMTB tramcar.
Has the name "Horrocks Roxburgh Pty Ltd Melbourne" on the base and "J.A. Floyd Maker Melb" in the centre.
Inscriptions & markings
has "551" scratched onto the rear.