REDWOODS, RAINFALL AND FOG 



183 



After some experimentation I developed the following as the 

 most convenient form for the apparatus. For the container 

 I used a 2 gallon galvanized iron kerosene can, with a screw top 

 3 or 4 cm. in diameter and a spout with a screw cap. This con- 

 tainer, fitted with the funnel as described, was found sufficient 

 to accommodate safely 225 cm. of precipitation. The can was 

 painted black to reduce its visibihty; notwithstanding which, 

 the inevitable small boy found and appropriated several. The 

 funnel was of the ordinary tin kitchen variety, the receiving 

 end being about 6 cm. in diameter. To minimize splashing 

 I added a vertical tin collar 2.5 cm. high, and a circle of coarse 

 ware netting was placed within to prevent clogging by debris. 

 The funnel was fitted to a hole in a cork stopper which in turn 

 fitted the opening in the top of the container. All joints were 

 made waterproof, and the top of the funnel was accurately 

 levelled after the apparatus was put in place. That these pre- 

 cautions are necessary is shown by the following table: 



Three further tests confirmed the approach to uniformity 

 indicated above. As a precaution, a small bent glass tube with 

 down pointing outer end was run through the cork beside the 

 funnel as an outlet for au\ It was thought that an exceptionally 

 heavy rain might so fill the tube of the funnel that no air could 

 escape through it, thus causing temporary overflow. I have no 

 means of knowing whether this is a necessary safeguard. The 

 funnels were numbered and the receiving area of each was com- 

 puted from the average of three diameters. Figure one shows 

 one of the instruments in position. 



Twelve instruments were set out October 18, 1913, and taken' 

 in May 13, 1914. Complete records were obtained from, seven, 

 and approximate records from four others which had disappeared 



