308 



THE MONTHLY BULLETIN. 



The first cuusideratioii is to get the materials hiyh enough on a plat- 

 form so that they can be easily and rapidly placed in the spraying 

 tanks of the power machines. This is done l)y constructing at conven- 

 ient places in the orchard, platforms large enough to hold a large 

 box for slaking lime, a lime solution agitator, and a vat for dissolving 

 the bluestone. Such a platform is about 12 feet square and 4| feet 

 high (Fig. 297). A large standpipe for filling the tanks is desirable 

 or the water must be pumped into the tank while the solutions are 

 being added. 



The lime is first slaked in a common vat for that purpose. The 

 great troulile has always been to keep the slaked lime agitated properly 

 when it was being drawn off to mix with the bluestone in the spraying 

 tank. This problem has been solved by the use of a special agitator for 

 this purpose (Pig. 298). The lime from the slaking vat is strained into 



Fig. 298. — Apparatus for prepaiing Bordeaux mixture. Tank for receiving lime 

 after it has been slaked and is ready to mix with the copper sulphate or bluestone. 

 The agitator is the special feature of this tank. (Essig, P. C. Jr. Bot. ) 



this tank through the slanting bottomed strainer. The agitator works 

 by means of a hand lever and the contents of the tank may be 

 thoroughly mixed in a few minutes before it is drawn off for use. 

 Here it is again strained through the strainer shown in Fig. 299 B, as 

 well as is the bluestone. 



The bluestone vat contains slats, across the entire box as shown in 

 Fig. 299 D, or simply across one end. These slats must be low enough 

 so that the bluestone, which is placed upon them in sacks, will be com- 

 pletely immersed in the water. This method admits quick dissolving 

 of the bluestone, much more rapidly than if simply poured into the 

 tank and stirred. 



The lime and bluestone are mixed with a given amount of water so 

 that the proper quantities of the resultant solutions can be measured 

 so as to give the mixture the strength of the above formula. 



The sieve used should be made of l)rass wire and contain twenty 

 meshes to the inch. 



This spray is usually used as a repellent for the flea-beetles, cucum- 

 ber beetles, diabrotica, and other leaf-eating insects. 



