Bourdon Gauge

Two glass tubes 220mm long x 8mm bore one closed at the top and other open. Lower ends of two glass tubes are joined by 1 meter of pressure tubing. Both tubes mounted on sliding brackets lockable in any position on metal support rods. Polished wooden stand with graduated scale 0-100 cms, with mms in centre and figured every cm on either side. Supplied without mercury.

A working model to demonstrate the principles involved in the action of a force-pump.

Cylinder is 25 x 350 mm dia x overall height. It is provided with a non-return float valve at its lower end. Lower part of the cylinder has an outlet side tube communicating with the lower end of another cylinder also equipped with non-return valve. Outlet tube from the secondary cylinder is drawn out into a jet to demonstrate ability of force pump to eject water at high pressure.