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Cylindrical

Plug type, with three pairs of ratio coils of 10,100 and 1000 ohms and 16 series coils from 1 to 5000 ohms, total 11,110 ohms, giving a range from 0.01 ohm to 1,111,000 ohms. Two tapping keys are provided for battery and galvanometer. Accuracy ratio coils ±0.05%, others ±0.1%.

For investigating transpiration. Measures the uptake of water by a cut plant shoot. The cut shoot may be replaced by a porous pot filled with water which enables measurement of the rate of evaporation from a moist surface, thus giving indication of relative humidity. Comprises a capillary tube with mm scale connected to a syringe and an outlet via a three way stopcock. The syringe enables adjustment of air bubble during set-up, the outlet is connected to the cut shoot or porous pot, mounted on strong vertical plate.

To demonstrate rates of transpiration and of water absorption by a cut shoot, with a graduated capillary tube bent down at right angle at one end with a small orifice and having water reservoir with glass stopcock and the end tube with rubber stopper for the plant shoot at the other end, on base.

A glass tube 15 mm dia with a side arm leading to a thistle funnel in rubber tubing has both its ends tapered and bent at right angles. One end would accept plant stem and the other is connected to a capillarty tube with mm scale, mounted on an L shaped stand.