REMEDIES AND PREVENTIVE MEASURES. 65 
here recommended. They have the advantage over all other means. 
that they kill directly the worms begin feeding, and at the same time 
have a preventive influence. Properly sprayed on the under side of 
the leaves so as to adhere, they are not easily washed off, and they not 
only kill, without injury to the tree, all the worms at the time upon such 
tree, but all those which may hatch upon such tree for a number of 
days and even weeks subsequently. 
Weare satisfied that with two or three special tanks, such as we have 
built at the Department of Agriculture, and a gang of three men to 
each, the trees of the city could be easily protected at a nominal cost be- 
eid labor, and that two sprayings, one about the middle of May and 
one the first week in June, will effectually prevent the repetition of any 
such nuisance as that we suffered from last summer. Each gang of 
three men could properly protect in the neighborhood of from three 
hundred to five hundred medium-sized trees per day, and in ordinary 
seasons and in dealing with the web-worm it would only be necessary 
to poison such trees as are preferred by the insect. 
We may here with propriety describe, as supplementary to the gen- 
eral consideration of machinery on pp. 19-22, two recently-invented ma- 
chines which could be used to advantage in this work. 
The first is the invention of Mr. A. H. Nixon, of Dayton, Ohio, and 
will answer very well for the spraying of arsenical solutions. The 
cyclone nozzle, with all its advantages on small or medium-sized trees, 
is not so well edapted for spraying very high trees, and Mr. Nixon’s 
nozzle and several others which might be mentioned have an advan- 
tage in that they throw a spray to a greater height or distance, in a 
more powerful and narrower stream, which nevertheless breaks up into: 
a floating spray. 
We have personally tested Mr. Nixon’s nozzle and find it is a very 
satistactory one. Mr. W. b. Alwood, the agent of the Division at Co- 
lumbus, Ohio, in a report upon it, writes: 
‘“The necessity of a good apparatus for spraying tobacco in a packing-house led Mr. 
Nixon to experiment with many different kinds of apparatus, until almost by accident 
he discovered that a jet of water projected against a wire gauze of proper sized mesh 
held at a certain distance would produce a perfect spray. He was several years in 
working up a scheme to utilize this newly discovered fact, and then succeeded very 
imperfectly, but produced an apparatus which found quite common use in his. and 
other tobacco warehouses in the Miami Valley. 
‘‘ However, some three years ago he conceived the notion of perfecting his nozzle and 
bringing it into shape for practical utility on a force-pump. In this I think he has: 
succeeded most admirably. Several styles of apparatus have been made by him for 
using his nozzle in practical work both in doors and out. Those designed for out- 
door work have especial reference to the destruction of insects. How useful these 
may prove I would not venture an opinion, not haying had a chance to use them in 
actual work, but of the fact that his nozzle will produce spray as fine or as coarse as 
can possibly be desired there is not the possibility of a doubt, and this, too, without 
any waste of liquid. 
‘“The pump used on his machines is a single cylinder double action force-pump of 
extremely simple mechanism and of great power and durability. 
