Gauge, Vacuum

a- Circular metal gauge with a broken glass front and an arrow counter that ends in a crescent shape, with numbers around the edges going from 0 to 30 in increments of 5. The manufacturers information on the front of the gauge is, "KNOWLES STEAM PUMP WORKS." It is also labelled with "REGISTERED AUGUST 21 1876" and "No. 7". It has a small threaded pipe coming out the bottom. b- A glass fragment that has fallen off the glass face of the gauge.