150 
BEPOET— 1847 - 
the machine, tending to lift it from its scat; it has therefore been proposed 
by M. Redtenbacher, Professor of Mechajiics at Carlsrulie, to obviate this 
inconvenience, when high falls are used, by making die axis horizontal, and 
fixing upon it two machines, introducing the water between them bymeam 
of a pipe formed like the letter T ; so that equal pressures acting in oppo¬ 
site directions may balance and neutralize each other. 
The axis or spindle connecting the two machines, and passing through 
the transverse pipe, is kept in a state of tension by the diverging forces. 
(See the figure.) 
Sectional Plan of a Double Mill; tlie opposite forces counteract and 
neutralise each other. 
The writer of this paper received the first account of the Turbine about 
fifteen years ago, when he was favoured with a visit of some days from Pwj 
fessor Wedding of Berlin, who described a turbine then recently erected 
under his own direction, the dimensions and a sketch of which he also gs’'®- 
He could not recollect the quantity of water expeirded, although he sialwl 
the useful efiect to bo 92 per cent, of the power employed. Mr. Glynn 
could not reconcile this part of the Professor’s statement, which appears ic 
have been made on a fev/ imperfect trials, with liis own experience in tb* 
use of water-power, for he had erected many water-wheels made entirely 
of iron, the performance of which was highly satiafactory* and was well-sf* 
quainted with many erected by others, cunsequentiy he Imew that the high¬ 
est effect had not exceeded 80 per cent., and that two-thirds of the po«<r 
expended was as much as could practically be reckoned upon. ThedimcD’ 
J^achine then given by Professor Wedding were as follows:— 
the fall or rather head of water was twenty feer, the diameter of the wbed 
three feet eight inches, the speetl 115 revolutions per minute, and thepowcf 
equal to forty-two horses, wliich drives eight pairs of ordinary mill-stowt 
widi all the requisite dressing machinery. 
We want only two facts to make this statement complete, namely, di« 
quantity of water expended, and the Quantity of com actually ground in * 
given time. 
Professor Wedding afterwards sent Mr. Glynn, from Berlin, & treatise 
which he had written in conjunction with M. Carliczeck on this subject, 
wherein several other similar machines are described, and the useful effect 
of the water is given at from 6S to 80 perx'ent.; which further experience 
on their part corresponds more nearly with our own practice in the useoi 
water-power. 
It H ill be seen that the great value of the Turbine consists in its being 
applicable to falls of water bo high or so low, that an ordinary water-whed 
cannot be used; and also, that in falls of great height, (the velocity of the 
