ON THE CONSTRUCTION OF BRICK ARCHES. 
297 
HOUSE-FLY GUARD. 
At the Entomological Society, on Monday, 
a paper was read by the secretary on exclud- 
ing the house-fly. d'he mode adopted was a 
net made of different coloured meshes of 
about three-quarters of an inch square, and 
which, when placed against a window, v/as 
found quite effectual in excluding the visits of 
these troublesome insects from the outside of 
the room. 'J’hesarne experiment was tried 
with meshes made of the finest black thread, 
one inch and a quarter square, which proved 
to be equally effectual. The approach of wasps 
was also prevented by the above mode, very few 
finding their way within the boundary. This 
was accounted for by an optical illusion in the 
eyes of the insect, of the highly magnifying 
power of vision, and the small focal length. 
MR. BRUNEL’S MODE OF CON- 
STRUCTING ARCHES WITHOUT 
CENTRING.— INSTITUTE OF BRI- 
TISH ARCHITECTS, l4TH MARCH. 
The secretary read a paper explanatory of 
M. Brunei’s mode of constructing brick arches 
out centring ; and also explained various ex- 
periments of that gentleman, with regard to 
the insertion of iron hoops in constructions of 
brick-work in cement. * * The principle, 
which was originally adopted, and its 
efficiency ascertained, in the formation 
of the shaft of the Thames with Tunnel, is 
founded upon the cohesive power of Roman 
cement, coupled with a system of ties, the 
most eligible substance for which, from a se- 
ries of experiments performed by M. Brunei, 
appeared to be hoop iron. The piershaving 
been • constructed in the usual manner, it 
is proposed to pin or secure to them a 
mould for the purpose of determining the 
contour of ihearch. A narrow rib may now be 
carried over, and keyed, using cement (with 
the occasional insei tion of ties), which, by its 
adhesion to the bric c being greater than the 
cohesion, enables the arch to he carried to 
any extent within the limits of the strength of 
the material. The several arches being in suc- 
cession, once keyed, they will be inastate to 
receive the whole of the materials necessary to 
the completion of the bridge. The bridge of 
the Santissinia Trinita at Florence was parti- 
cularly adverted to, affording a magnificent 
example of rubble construction, and the dura- 
bility of the material. The arches are com- 
posed of a mass of irregular stones embedded 
in mortar, having the consistence of a single 
stone, or of two stones abutting against each 
other at the crown.— Ed. Arch. Mag. 
MACHINE FOR CUTTING SAUSAGE 
MEAT, and stuffing SAUSAGES, 
ABRAHAM AND JOHN KEAGY, 
PENNSYLVANIA. 
The cutting is effected by means of a 
cylinder, around which are placed knives 
which we usually make of a triangular form, 
one of the sides being in contact with the 
cylinder. This revolves within a concave, 
or hollow cylinder, furnished with similar 
knives so placed as not to interfere v?ith 
those on the cylinder. These knives are but 
placed somewhat obliquely, so as to stand ia 
the direction of a spiral around the cylinders. 
'1 he revolving cylinder has its axis placed 
horizontally in a box, the sides and ends of 
which are enclosed excepting where the meat 
is admitted and discharged. A gudgeon pro- 
jects through the box at one end to receive 
a crank of wheel to turn the cylinder. 
The opening for feeding is on the upper 
side, and at one end of this box ; and this 
opening is surmounted by a vertical trunk, 
which may be in the form of a parallelogram, 
of the.width of the lower box, and about half 
its depth, more or less. A piston, or follower, 
is adapted to this feeding trunk, or hopper, 
from the middle of which a rod rises, operating 
as a piston rod, being acted upon by a lever, 
worked like a pump-handle. The piston rod 
passes through the lever, and has a rack, or 
notches, upon it, which engage with the lever 
in its descent, but allow it to rise without rais- 
ing the piston, so that the meat put into the 
feeding-trunk is forced down by each succes- 
sive stroke. To facilitate the passage of the 
meat into the horizontal, from the vertical 
trunk, I form a spiral excavation in the hollow 
cylinder, immediately under the vertical 
trunk ; which operates as an inclined plane in 
producing the desired effect. The cut meat, 
when it airives at the extreme end of the cut- 
ting cylinder, passes out through an opening 
in the bottom of the box. When the feeding- 
trunk is to be replenished, the lever may be 
turned back on its joint, and the piston re- 
moved, leaving the opening perfectly free. 
When the cutting has been completed, the 
vertical trunk, with its piston, is used for the 
purpose of stuffing. To effect this, a shutter, 
or slider, is slipped into its place where it 
forms a bottom to the vertical, and cuts off its 
communication with the horizontal trunk, and 
a tin, or other tube, of proper size, is' fitted 
into an opening prepared for it on one side of 
the trunk, at its lower end; upon this tube the 
entrail to be stuffed is gathered in the usual 
way. 
To allow the escape of.air, this latter tube 
has a small tube, or opening, soldered on its 
outside, from end to end. This' opening may 
he semicircular, so as make but a slight pro- 
jection on the stuffing-tube. The effect of 
this will be obvious. 
We have not thought it requisite to give 
the dimensions of the respective parts, as they 
will vary according to convenience, and will 
depend upon the power to be applied, and the 
quantity to be cut. One thing, however, is 
essential, namely, that the length and size of 
the cylinders, and the number of knives, be 
proportioned to the quantity to he cut ; but 
this can be regulated also by the pressure made 
upon the piston. 
