This apparatus is designed to demonstrate to students that volume of air enclosed in the column is clearly visible to students. A wide bore glass tube is mounted vertically in front of a scale graduated 0-60 cm. Zero corresponds to the inside of the closed top end of the tube. Air is confined in the tube by a coloured oil contained in a metal container fitted with a Bourdon type gauge. A tap is fitted to the side of the metal container, for the air inlet tube from the pump. As the pressure in the oil container is increased, oil is forced into the glass tube and volume of contained air and its actual total pressure are directly indicated. The tube is of extra strong glass having very large safety overload margin. As a further precaution, a safety plastic screen is secured over the front. Overall ht. 690 mm approx. Supplied complete with oil.

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.

Comprising glass U-shape 15 mm dia with one plain limb 220 mm long one graduated limb overall length 120 mm. Limb graduated 25 to 35 x 0 2ml terminating in a bulb 37 mm dia.with third limb 185 x 6mm (length x bore), jointed at right angles to the plain of the other two. Short length of the rubber tubing with two pinch clips of on short length of glass tubing mounted In end of wide-bo Plain limb with rubber bung. With tall farm beaker 1000 ml capacity and stirrer. All glass parts made from Pyrex glass.