542 
manufacturing’ machinery. 
of the sails, and the distances from each 
other, must bé so regulated as that the 
wind may strike the sai! sufficiently at- 
the same time, so as not to make the 
angle of the line of the sails with the 
wind too-great. The sails mist be made 
full, so as-to form a concave surface to 
the wind. The machinery fora floating 
tide, or current mill of: great power, 1s | 
forined similar to that above describéd, 
only allowing’ the lower sails to repre- 
Sent the floais of this, and the water to 
flow towards the point on which they 
act. These floats may be ef wrought 
iron, or other materials, and wil! in gene- 
ral be broader than deep; though, as in 
the wind-mill, they mnust form a concave 
surlace to the current, which, if running 
only one way, the concave side ‘of the 
float must be $0 fixed; but, as<in the 
case of tides where the stream flows 
both ways, it is made to turn on a pivot 
m the centre of the*frame, above and 
below. © The floats should always be 
made as deep as the currént will admit 
of, for im this, as in thé wind-mill, power 
is gained without losing time. The drum- 
wheels, chains, and axles and wheels, 
are the same as for the wind-mill, butas 
water is a steadier power than wibd, the 
Springs are not required for this. The 
machinery for cattle-mills'is on the same 
principle as for the wind and floating 
tuills, being a connection of plauks united 
Sige ak EER 
PROCEEDINGS OF LEARNED SOCIETIES, — 
Soe ot tik ey. a eae heey ele 
Proceedings of Learned Societies. 
The width” 
[Jani-1y' 
by joints, and having at their ends wheels — 
travelling ina channel of the framing 
round two drum-wheels, to the axle of — 
which is fixed the manufacturing machi- ” 
néry, The drum may, if preferred, be 
placed lower than at the head of the 
horses, so as to cause the cattle to act 
in part by their gravity, as upon an in- 
clined plane. The cattle drawing from 
a fiwed point, and pulling round the” 
dram-wheels with the machinery by the 
power of their feet, enables them to 
work constantly in a straight line, by 
which means they travel much faster, 
with greater ease, and performing more 
work, than by being constrained to tra- 
vel round a circle. 
~The Patentee observes at the con- 
clusion of his specification a$ follows: ‘Tt 
may be necessary for me to observe that - 
there is a similarity in appearance be- 
tween my plan of working mills by a fall 
of water, and a method published many 
years ago by Dr. Desaguliers. Had the 
doctor’s method proved useful for mo- 
derate or small falls, or perfect for great 
falls of water, any other plan might have 
been unnecessary, but the machinery: is 
defective. The ffiction and obstructions 
operate too much against the power 
gained; and though, im very extensive 
falis, the disadvantages are less in propors 
tion, they are too great to be of general: 
ulilicy 22 ee 
vi 
OIA 
See 
ROYAL SOCIETY OF LONDON, 
We are now to pursue the facts Jaid 
' “before this Jearned body by Mr. 
Davy, respecting the metals of the earths, 
on which ‘he madé a variety of experi- 
ments, in hopes of gaining the same dis-_ 
tinct évidencés of the decomposition of 
the common eartlis, as those afforded by 
the electro-cheimical processes. on the 
alkalies, and the alkaline earths. When 
irou-wire, ignited to whitenéss by the 
power-of 1600 double plates, is nega- 
tively electrified and fused in contact 
with either silex, alumine, or glucine, 
slightly moistened and placed in hydrogen 
gas, the iron becomes brittle and whiter, 
and affords, by solution in acids, an earth 
of the same kind as that which has been 
employed in the experiment. Mr. D.. 
passed potarsiuprin vapour through each 
of these earths, heated to whiteness ip a 
platina tube, and the results were ree 
markable, When silex was employed 
in the proportion of ten grains to four ef 
potassium, no gas was evolved, the po- 
tassium was entirely destroyed, and giass, 
with an excess of alkali, was formed in 
the lower part of the tube: when this 
glass was powdered, it exhibited dark 
specks, having a dull metallic character 
not uulike the’ protoxide of iron. “When 
the mixture was thrown into water, there 
was only a very slight effervescence; but, 
on the addition ef muriatic acid to the 
water, globules of gas were slawly libe.- 
rated, and the effect conunued fur nearly 
an hour, so that there is reason to infer 
that the silex had been either entirely or 
_ partially deoxygenated, and was slowly 
reproduced by the action of the water, 
assisted by the slight attraction of the 
acid for the earth. Potassium, in acting’ 
upon alumine and glucine, produced more 
bydregen than could be ascribed to the 
(Co. ae a One moisture 
