Report on the Trials of Implements at Reading. 651 
mechanism. The hand-shaft passes through the upper jxirt of the centre of 
the box ; it is fitted with a wooden handle at each end, and worlcs in bearings 
secured to the sides of the box. On the same side with the fan the hand-shaft 
passes through a short sleeve bolted to the side of the box, and carrying a small 
bevel pinion, Fig. 1 (a). This gears into a pinion of the same size (b), revolving 
freely round a stud secured to the lower "p-piecc (c), which is free to revolve 
round the hand-shaft. Secured to the pinion (b) is the larger bevel-wheel (d), 
which engages into a wheel (e), secured to a large driving-wheel which runs 
loose on the hand-shaft. This driving-wheel has an annular rim on one side 
of it, and on its bottom part run two friction rollers that are kept together by 
means of a pair of levers, the upper ends of which are pivoted to the casing, 
while the lower ends are held together by means of a spiral spring with 
screw adjustment ; between these rollers comes a leather-covered pulley, 
keyed on to the far spindle. The rollers are kept in their places by the edt^e 
of a ring bolted to the driving-wheel, and running in grooves formed in the 
rollers. The ratio of speed between the handle and the fan is 49 : 1, so that 
at 30 revolutions of the handle, a very moderate speed, nearly 1500 revolu- 
tions of the fan can be obtained. This apparatus is by no means easy to 
work, and very unnecessarily complicated. 
Fig. 1. — Illustrating the Working Parts of Greening's Fan, No. 4394. 
The flue used with this fan is a half-round sheet-iron tube, 
10 inches in width at the inner end and decreasing gradually to 
about 6 inches. The junction with the fan is effected by means 
of a flexible tube. 
The exhibitors claim for this fan that, without being large, 
heavy, or cumbrous, it attains a great velocity, 45 revolutions of 
the handle giving 2430 revolutions of the fan, and 40 turns of 
the handle giving 2160 of the fan ; but this speed is obtained by 
