the Philadelphia Centennial Exhibition. 
G9 
ceding illustration (Fig. . r >7) and the following particulars, which are given in 
the descriptive catalogue. 
A, is a strong casting, bolted to the timber, and further stayed by two 
braces E, E. The turntable B is large, has friction side rollers and is carried on 
four friction-balls; this allows of freedom of motion according to the state of 
the wind. C is the spider to which the arms or spokes of the wind-wheel are 
bolted. This spider is firmly keyed to the shaft which rotates in babbit- 
lined boxes on the turntable. This shaft terminates at the centre of the turn- 
table, carrying the crank-plate M, to which is attached the pitman L, which 
operates the pump. The sliding-head D is connected to the elbows Y by a 
link from each. To the outer end of the elbows Y, are attached rods which are 
attached to the centre of each wing, and have a small balance weight behind 
this attachment, operating out or into the wind, as the lever F is raised or 
depressed. The action is the same as that of the governor on an ordinary 
strum engine. By means of rod R and lever S the mill can be stopped from 
below ; when the force of the wind increases the revolutions, the centrifugal 
force, as has been said before, overcomes the resistance, owing to dead weight, 
and the sections fly open. This will be better understood by the subjoined 
sketch, which represents a section of the rosette as at work (Fig. 58). The 
side of the sail A has a greater area 
than B, hence a sudden dash of gusty Fig. 58. — Section of a Bosette 
wind turns the sails out of the wind by a i wor Jc, 
pressure on A. Just on the same plan 
as a weather-cock. It is a curious fact 
that in small mills the wings being all 
of wood, the outer part being broader 
and heavier than the inner, it will get 
up too rapid motion, and the remedy is 
an iron weight on B ; whereas in larger 
mills of 20 feet diameter, for example, 
the pace is too slow, and the weights 
must be hung on the broad outer wheel at A. The explanation of this is 
that centrifugal force is so great in small wheels that it overcomes the direct 
pressure of wind against the wing, and in larger circles centrifugal force 
is so much less that it will not without extra assistance prevent the wind 
from blowing the wings out of the wind. These mills are sensitive, and 
probably do more duty for a given wind than some others. The drawbacks 
are the complication of parts, requiring more attention in oiling, and the 
additional cost. 
The Eclipse Wind-Mill Company, of Belvit, Wisconsin, manufacture Wheler's 
Patent Wind-Engines, which have a perfectly solid rosette wheel and are other- 
wise simple in construction. The peculiarity consists in an adjustable inside 
vane, which acts as an overbalance, and draws the rosette away from the wind, 
bringing it, in the case of a very heavy storm, nearly in the same line as the 
back vane. It is claimed that by this arrangement the wheel is always — i. e. 
in a moderate breeze — kept facing the wind, because the action of the vane 
to draw the rosette away, must first overcome the leverage of a weighted arm, 
the weight on the same being adjustable. The engine can be quickly stopped 
by pulling down the lever, which brings the wheel edge to wind. The turn- 
table travels on four friction-balls, running on a grooved surface. The table 
casting is in one piece with the cap or bed-plate, and has flanges on the 
under-side, which receive the head of the post. All the parts are numbered, 
and can be readily fitted together. This appeared to me a simple well-made 
wind-engine. 
E. Stover and Brothers, Freeport, Illinois, also employ the solid rosette. The 
wheel being dished inwards, and strongly supported by the felloes, which, are 
