AN IMPROVED METHOD OF AND APPARATUS FOR PRODUCING VACUUM IN NIGHT CARTS, USED IN REMOVING FECAL MATTER
Year: 1872

page_text: PROVISIONAL SPECIFICATION left by Pierre Varnaison at the Office
of the Commissioners of Patents, with his Petition, on the 23rd
August 1872.
I, PIERRE VARNAISON, of Boulevard de Strasbourg, 23, à Paris, do
hereby declare the nature of the said Invention for "AN IMPROVED
METHOD OF AND APPARATUS FOR PRODUCING VACUUM IN NIGHT CARTS, USED IN
REMOVING FECAL MATTER," to be as follows:-
This Invention relates to night carts, in each of which there is a
vacuum to enable the atmosphere to force the focal matter into its
interior, and the different methods hitherto proposed for making the
vacuum in the night carts, whether by means of water or the direct ex-
haustion of air by air pumps, leave much to be desired with respect to the
To avoid
night soil itself, and also the speed at which it is removed.
these inconveniences attempts have been made (but without success)
to apply these modes of making the vacuum in the night carts before
they depart to the place where they are to be used, and the object of my
Invention is to make this mode of operating successful by means of
improved arrangements of machinery or apparatus.

page_text: The principle of my Invention consists in the employment of an inter-
mediate vacuum vessel in almost continuous communication with the air
pumps and also at the required intermittent times with the night carts.
The non-interrupted play of the pumps maintains a permanent
vacuum in the vessel in such manner that when the cart is joined to it
the air rushes from-the-cart-into the vessel_and_the vacuum is rapidly
obtained, after a small number of strokes of the pistons of the pumps.
The task of the vacuum vessel can be compared to that of the
accumulator used in hydraulic presses, for in both cases by using the
intermediate vessel there is the double advantage of not requiring any
interruption in the working of the pumps and increasing the effect to be
produced, and thus there is no loss of time in stopping and putting on
the pumps, and the vacuum is effected with extraordinary speed and
facility.
My system is characterized by other peculiarities, such as the special
arrangement and construction of the pumps in the taps at the junctions
and in carrying off by a chimney the air from the night carts, the air
being often foul and deleterious.
The vacuum vessel is formed as a cylinder having convex or spherical
ends, and has at the top a tap connected to a pipe which by two branch
pipes communicate with the exhaust pumps placed in the interior of a
chamber containing water, and surmounted with a compartment con-
taining oil for the purpose of preventing the entrance of air to the
pumps, and the piston of each pump is made of copper or bronze metal
packed with a leather or india-rubber ring for making the piston tight
with but little frictional surface.
The air drawn from the vacuum vessel by the-rising-of-the-piston of
cach pump-raises a-valve at the bottom, and escapes through a valvo
in the piston, when the latter descends to other pipes loading to the
chimney,, where the noxious gases are burned, so that the operatives do
not suffer from the deleterious air contained in the carts.
The piston rods of the pumps are jointed to connecting rods.worked.by...
cranks or eccentrics on a horizontal shaft having a driving pulley outside.
the chamber, and the vacuum vessel is provided at one or both. sides with
several taps, each being connected. by a pipe with a tap on the top of the
night cart, which as in the ordinary way is mounted on a frame and

page_text: wheels and has at the bottom two apertures one for the filling and the
other for the discharging.
When by the working of the pumps the vacuum is maintained in the
vacuum vessel the carts are attached to it, and when the taps are opened
there is a vacuum in the carts, in about three minutes after which the
taps are closed, and the cart removed ready to be sent off to the town to
be filled with focal matter.