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diameter, and was large enough to inclose a tree at least 24 feet high. It had been 
oiled with boiled linseed oil, to each gallon of which 1 pound of melted beeswax had 
been added for the purpose of rendering the cloth more durable. The sheet, when 
completed, cost about $75. 
The apparatus for placing this sheet over the tree consists of two upright poles, to 
the top of which are attached the pulleys through which pass the ropes used for 
hoisting the sheet. The uprights consist each of a pine scantling, 3 by 4 inches in 
diameter and 24 feet long. A crosspiece 5 feet long is bolted to one end of this 
scantling, with a brace extending from each end of the crosspiece to a point on the 
scantling a few feet from its base; this crosspiece is for the purpose of preventing 
the scantling from falling over to one side when it is raised to a perpendicular posi- 
tion. These uprights are very light affairs, and one man can carry them about with 
ease. 
When the sheet is to be placed upon a tree, it is brought close to one side of the 
tree and thrown upon the ground. The two uprights are next elevated on opposite: 
sides of the tree from each other, and leaned until their upper ends are nearly above 
the sheet as it rests upon the ground; a stay rope attached to the upper end of each 
upright and held by men stationed several yards from the base of the uprights, and. 
in an opposite direction from the sheet, prevents the uprights from falling over in 
one direction, while the crosspiece at the base of each upright prevents it from fall- 
ing over sidewise. The hook at the end of the rope which passes through the pulley 
at the upper end of each upright is then hooked into an iron ring fastened to a rope 
that is sewed across the tent about 6 feet from its edge; the opposite ends of the 
ropes passing through the pulleys are then drawn downward until the sheet is drawn 
to the upper ends of the uprights, after which these ropes are fastened to the braces 
on the uprights, and the men holding the stay-ropes draw the tops of the uprights. 
toward them, thus drawing the sheet over the tree, and after it has been drawn far 
enough, the lower ends of the ropes passing through the pulleys are unfastened and 
the sheet allowed to fall down over the tree, the uprights at the same time being 
allowed to fall flat upon the ground. 
When the sheet is to be removed from the tree this can be done either by hand or 
by the use of the uprights, and if each tree in the row is to be treated the sheet canbe 
drawn off of one tree and placed over the next without the necessity of lowering 
the uprights, since one man can carry the foot of the upright several feet forward. 
with ease at the same time that the sheet is attached to the top of it. 
Five men can operate this apparatus with less labor than is required to manipu- 
- late the fumigators now in use, and by the one pair of uprights and ropes at least 
half a dozen sheets could be operated by the one set of men, without any loss of 
time. Iam informed that the cost of this apparatus, including half a dozen sheets. 
large enough to cover trees 24 feet high, will not exceed $450, this being only about 
one-third of the cost of fumigators for operating six tents as at present used. 
This sheet-fumigator can be used in places where the ordinary kind could not be 
used; forinstance, on steep hillsides, or among trees planted so closely together that 
an ordinary fumigator could not be driven between them. The sheet, in being 
pulled off of the tree, does not catch beneath the branches, as the ordinary tent is 
very liable to do. 
As this new fumigator can be easily constructed by almost any fruit-grower, we may 
reasonably expect that this method of destroying scale-insects will come into more 
general use.—[D. W. Coquillett, California, March 18, 1892. 
Life-history of and Remedies against the Mosquito—The House Fly. 
Will you be so kind as to give me the life-history of the Mosquito—hibernation, 
duration of life of individual, and best means of preventing their propagation? I 
desire to impress upon our citizens the importance of destroying the first brood of 
‘injurious insects that appear in spring. 
