Mr Hill’s Improvement on the Manufacture of Starch. SOS 
with their lower parts immersed about one foot under the water 
in the channel. In stormy weather, the’apertures of the channels 
may be shut by sliding shutters ; and, if necessary, the water 
may be pumped out of the channels, so that the wheels are en- 
tirely closed in. The patentees state, that it may be sometimes 
desirable to form trunks on the outside of the vessel, in place of 
the channels above described. This patent appears to rest on 
the use of channels closed up every where, except at the en^ 
trance and exit apertures, on the use of several pairs of paddle-^ 
wheels, , and on the power of shutting up all the propelling ap- 
paratus by means of sliding shutters 
16. Account of Mr Hil£s Improvement on the Manufacture of 
Starch. 
The object of the patentee is to deprive the starch of all its 
colouring matter, and render it perfectly white, by the action of 
the oxymuriatic acid. When the starch is ready for boxing, 
it is reduced with water to the consistence of cream. The oxy- 
muriate of lime is then added to it, and the whole continually 
agitated. A large quantity of water ,is [next added ; the mix- 
ture is well stirred, and the starch allowed to subside. The 
water is then drawn ofp, and diluted sulphuric acid poured upon 
the starch, and the whole agitated for some time. The starch 
is finally washed with repeated quantities of clear watpr, till all 
smell is removed from it. 
17. Account qf Mr Ward's Alternating Steam-Engine. 
In a preceding volume (Vol. I. p. 348.), we have described 
the steam-engine of Mr Morey, in which the cylinder revolves 
along with the axle of the paddle-wheels. Mr Ward, an Ame- 
rican ^gentleman, seems to have improved this construction. This 
new engine, as applied to steam-boats, is represented in Plate X. 
Fig. 7., where the cylinders hjh are placed within the water- 
wheel cc which revolves round axes or centre-pieces at fixed 
to the boat dd, and join on each side of the recess for the wheel. 
These centre-pieces, after traversing the boxes, are turned at 
* Fuller descriptions, with drawings of these two inventions, will be found in 
fhe London Journal of Arts ^ vol. ii. p. 401. and 405. 
