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ience they may be divided into three classes: (1) horse-power automatic 
machines, (2) machines drawn by horse power, but operated by hand, 
and (3) hand machines. All belonging to the first group may be dis- 
missed with the statement that they are unnecessarily expensive and 
complicated, and will not, even in the most careful hands, do the work 
as thoroughly and effectively as the machines belonging to the second 
and third groups. Of the second group,in which the cheapest, most 
practical and efficient example is found in a strong, light, double-acting, 
double-discharge force pump mounted on a barrel, it may be said that 
while they can not do the work as rapidly as the machines of the first 
class they are more effective, much cheaper, and far less wasteful of the 
liquid used. ‘To the third class belong the knapsack sprayers, which 
are the only ones necessary to notice in this connection. There is no 
question that for all moderately low-growing crops the knapsack sprayer 
fills every requirement. In no other machine is the work so absolutely 
at all times under control, it being possible to place nearly every drop 
of liquid exactly where it is wanted. Knapsack pumps are now used 
in many moderate-sized vineyards; also in places where the horse-power 
apparatus, owing to the nature of the land or the manner of cultivation, 
can not be utilized. 
Many firms throughout the country, as will be seen by reference to 
the columns of any good agricultural paper, are engaged in the manu- 
facture and sale of the various machines mentioned. 
Taking up the question of spraying more specifically we would call 
attention first to apple diseases and their treatment. 
TREATMENT OF APPLE SCAB. 
For this disease either modified eau céleste or ammoniacal solution 
of copper carbonate, preferably the former, may be used. At least four 
sprayings should be made, the first just as the flowers are opening, the 
second twelve or fourteen days later, and the third and fourth at similar 
intervals. In case the season is wet one or two additional treatments 
will undoubtedly pay. For trees 15 to 18 feet high the cost of four 
sprayings with either of the fungicides mentioned need not exceed 20 
cents per tree. When the work is done on a large scale 16 to 18 cents 
per tree will cover the cost of four treatments. Two additional treat- 
ments will add to the cost from 6 to 8 cents per tree. 
APPLE POWDERY MILDEW. 
It is only in nurseries that this disease is destructive. Seedlings are 
especially subject to the mildew, the leaves being attacked as soon as 
they appear. Asa result the trees make very little growth, are bark 
bound, and consequently unfit for budding. The ammonical solution 
has proved the cheapest and most effective remedy for this disease, 
and five sprayings seam to be required. The first application should 
