_Preparation of Bordeaux mixture._--Formula: Copper sulphate (bluestone), 5 pounds; lime, 5 pounds; and water, 50 gallons. The copper sulphate may be either in crystals or pulverized. Dissolve by suspending the required amount in a coarse sack near the top of the water a few hours before it will be needed. The lime must be fresh stone lime of good quality. Slake thoroughly by the addition of small quantities of water at a time as needed, stirring until all small lumps are slaked. Strain both the lime milk and the copper sulphate or bluestone solution through a brass strainer of 18 meshes per inch and dilute each with half the water before mixing together. Do not use Bordeaux left over from the previous day. An old mixture or one made from the concentrated solutions has a poor physical condition. It settles more quickly, tends to clog the nozzle and does not adhere so well to the foliage. Failure to use the strainer results in endless trouble in the field from clogged nozzles. [Illustration: FIG. 42--PROPER WAY TO MAKE BORDEAUX (From W. G. Johnson)] When much spraying is to be done it is more convenient to keep the bluestone and lime in separate permanent stock solutions, as shown in Fig. 42, containing 2 pounds to the gallon of their respective ingredients. These will keep indefinitely, if the water evaporated is replaced, and may be used from as needed. _Spraying apparatus._--Tomato growers having only a small area to spray may use one of the numerous forms of hand-pumps or bucket sprayers now on the market. For larger fields it will be necessary to employ a barrel sprayer. This consists of a hand-pump mounted in a barrel or tank and equipped with two leads of 3/8 inch hose 25 feet long, each with a four-foot, extension made from 1/4 inch gas pipe, and a double Vermorel nozzle. The barrel should be carried in an ordinary farm wagon. Three men do the work. One is expected to drive and pump, while the other two manipulate the nozzles. The outfit is stopped while the plants within reach are sprayed, then driven forward about 30 feet and stopped again. On an average in actual field practice 3 to 4 acres a day can be sprayed in this way, applying 100 to 200 gallons of Bordeaux per acre. To keep the long hose off the plants two poles about 10 feet long may be pivoted to the bed of the wagon so as to swing at an angle over the wheel and carry the hose. The pump for this outfit should be of good capacity, with brass valves. A "Y" shut-off discharge connection on the pump is a convenience for stopping the spray at any time. The most satisfactory nozzles are those of the Vermorel type. It is cheapest in the long run to buy the best grades of pumps on the market. This outfit is excellently adapted for spraying small fields of potatoes and for general orchard work, and is invaluable on the average farm.