1 8 FRUIT TREES AND THEIR ENEMIES 



to the top, and therefore, if the Hquid is not con- 

 stantly agitated, a very unequal distribution of 

 material results. Some of the more recent machines 

 contain an automatic agitator, which is worked by the 

 pump itself : in the case of the knapsack sprayer, the 

 motion of the man who carries it is generally sufficient 

 to keep the liquid shaken up. The second precaution 

 is that the sprayers after use should always be 

 thoroughly washed out, pumping water through them 

 for the purpose, as many of the liquids used corrode 

 the metal and the rubber of the valves. 



Spraying machines are now to be had with wooden, 

 instead of metal tanks, and these present the advan- 

 tage of it being possible to use the tank for making 

 Bordeaux mixture, instead of having to make this in 

 a separate vessel. 



It is hardly necessary to mention that spraying can- 

 not be done efficiently on a windy day. Even on a 

 calm day it is not always a pleasant operation, 

 especially when caustic washes are being used, and 

 great care should be taken to prevent the workmen 

 from being injured by these. The men should be 

 provided with waterproof capes, broad-brimmed hats, 

 and india-rubber gloves ; and it is well to have a basin 

 of vinegar and water handy to neutralise the alkali, 

 in case any of it gets on to their faces or hands. 

 When spraying lime-washes, the men should be pro- 

 vided with coloured glasses, and these should also be 

 worn while making up any washes with caustic soda, 

 as if the strong alkali splashes up into the eyes, the 

 consequence may be serious. 



Powders are distributed on trees by being blown on 



