270 On the Rain and Drainage - Waters at Rothamsted. 
carried 3 inches above the level of the soil, the edges at the 
top being made to slope outwards. A sketch of the three drain- 
gauges will be found in Fig. 2, which also shows the position 
of the large and small rain-gauges. 
Fig. 2. — View of the Bain- and Drain-gauges. 
At about 1 foot G inches buluw the ])c-rfurated iron bottom is 
fixed a large zinc funnel, of the same area as the soil above it ; 
the drainage-water from the soil falls on to this funnel, and is 
received in suitable vessels placed beneath. During the first 
three years the water was collected in glass carbojs, and its 
quantity determined by weight ; but since December, 1873, 
galvanised-iron cylinders, fitted with external gauge tubes, have 
been employed for receiving and measuring the water ; these 
cylinders are quite similar to those used for the large rain-gauge. 
