64 
side ofthe box opens with a hinge, to 
admit the dough, and the box is turned 
round. ‘he time requisite to produce 
fermentation depends on the tempera- 
ture of the air, the quickness of the 
turning, and other circumstances. 
But, when the operationis performed, 
it is known by the shrill hissing of the 
air making its escape, which generally 
happens in half an hour. ‘The leaven 
is always extremely well raised ; per- 
haps too much, sometimes, The la- 
bour is nothing, for the machine, such 
as this here described, may be turned 
by achild. No hooks, points, cross- 
bars, or any other contrivance, can be 
wanted within the box, to break or se-~ 
parate the mass of dough ; for these 
operations are sufficiently effected by 
the adhesion of the dongh te the sides 
New Patents and Mechanical Inventions. 
[Aug. I, 
of the box. If the machine be made 
of greater length, and divided by cross 
partitions at right angles to the sides, 
different kinds of dough may be pre- 
pared at the same tinie. One evident 
advantage of such a contrivance is, 
that bread, manufactured in this way, 
must be perfectly clean and free from 
any accidental soiling. 
“UNITED STATES. 
The last letters state, that the sea 
serpent has at length teen entangled, 
and killed, on the coast of New Eng- 
land... It measured forty feet in length, 
and was eighteen in circamference. 
An American has discovered the 
principle of a new firelock, by which 
a soldier can fire fifteen charges, as 
fast as he can ¢ock and pull the 
trigger. 
NEW PATENTS AND MECHANICAL INVENTIONS. 
— 
CAPTAIN BROWN’S SUSPENSION BRIDGE 
ACROSS THE TWEED. ( With an En- 
graving. ) 
A‘ this day, the common mode of 
crossing rivers and ravines -in 
South America, and the inland terri- 
tory of Hindostan, is by means of 
ropes of various kinds, stretched from 
side to side, on which a roadway is 
wenerally formed for the traveller and 
his equipage; though, in some in- 
stances, there is only a single rope, 
from which he is suspended in a 
basket, and drawn across, while his 
mule fords the stream, or clambers 
through the ravine. The earliest 
bridges of suspension of which we have 
any account, are those of China, said 
to be of great extent; Major Rennell 
also describes a bridge of this kind 
over the Sampoo in Hindostan, of 
about 600 feet in length. But the first 
chain-bridge in our own country, is 
believed to have been that of Winch- 
bridge over the river Tecs, forming a 
communication between the counties 
of Durham and York. In this miscel- 
lany, for January 1797, we inserted 
the specification of a patent, and a 
view of a suspension-bridge on a dif- 
ferent plan, by Mr. Jordan, but we 
never heard of the adoption of his 
principle. It appears from a treatise 
on bridges by Mr. Thomas Pope, of 
New-York, that eight chain-bridges 
have been erected upon the catenarian 
or suspension principle, in different 
parts of America. He describes a 
bridge of this construction over the 
river Metrimiiek, in~ Massachusets, 
consisting of a catenarian ér sas- 
pended arch of 244 fcet span. The 
road-way of this bridge is suspended 
between two abutments or towers of — 
masonry, thirty-seven! feet in height, 
on which piers ‘of carpentry are 
erected, which are: thirty-five feet in 
height. Over these ten chains are 
suspended, each measuring 516 feet in 
length, their ends being sunk into 
deep pits on both sides of the river, 
where they are secured by large 
stones. ‘The bridge over the Merimack 
has two carriage ways, cach of fifteen 
feet in breadth. It is also described 
as having three chains, which range 
along the sides, and four in the middle, 
or between the two roadways. ‘The 
whole expence of this American work 
is estimated to have been 20,000 dol- 
Jars, and the bridge calculated to sup- 
port or carry about 500 tons. 
The Union-bridge represented in 
the engraving across the river ‘Tweed 
at Norham Ford, is about five miles 
from Berwick. It was begun in 
August 1819, and was opened in July 
1820, while a stone-bridge would have 
been the work of about three years. 
The roadway is made of timber, on 
which iron cart-tracks are laid for the 
carriage wheels. Itis eighteen feet in 
width, and 361 feet in length. The 
mainbeams or joisting measures fifteen 
inches in depth, and sevew inches in 
thickness. The timber cleading or 
planks are twelve inches in breadth, 
and three inches in thickness. ‘This 
great 
