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Flash P. Dec:r 1793
Flash & Steam
Engine
The power of a
Steam Engine is
limited by the Diameter
that can
be given to the Piston:
that of a Flash
Pump has no limitation.
Steam can not
act but in proportion
as it is compressed
and prevented from
escaping confined.
The pressure is
between the surface
of the water and
the bottom of the piston.
Do what you will
with the steam, it
can not act but in
proportion as it applies
itself to an
obstacle. moving in reciprocating
a channel. Its
power will therefore
be limited by the
diameter that can
conveniently be given
to the channel and
by the weight or
other power of resistance
that can be
given to the obstacle
Collect the Tables
giving the proportion
of expansion in air
to the quantity of
caloric applied to
it
As the oxygen is
but 1/4 of the air
no more 'caloric
can be applied
than is contained in
that 1/4 part: even
supposing the fewel to
be applied as to
employ the whole of
the air.
But the increase
of temperature resulting
from the decomposition
of that quantity
of oxygen is
known by Lavoisiers
experiments: and if
the degree of expansion
is likewise known
this will shew the
utmost proportion
of air that can be
driven out by a
flash.
If the first flash
has been perfectly
performed, nothing
can be gained by
a second but in proportion
as the air
has been changed in the
---page break---
the flash-chamber
since the first flash.
Apply a Winnowing
Machine -
Making the Chamber
Square the
length of the Winnowing
machine
may be the length
of a side of the Square
But in this plan
in would be better
the square should
be an oblong Square :
that the ventilation
may be the more
speedily performed:
especially if the bulk
of the chamber be
considerable
How to give admission
to the water
when the expansion
is at its maximum.
The expansion
opens a valve
On the ceasing of
the expansion the
valve closes.
The closing of the
valve opens the
sluice which lets
in the water.
The valve must be
as sensible as possible.
It must consequently
be distinct from the
great valve for which
gives exit to the air.
In the Steam Engine
the Chamber must
be cast all in one
place viz: of Cast
Iron at the cheapest.
That iron must be
of great strength and
of a strength increasing
in proportion to
the power of the steam
that is in proportion
to the size of the
Chamber
In the Steam Engine
the whole of the water
in the Boiler must
be brought to the Boiling
Heat before any
steam is formed - before
any power is
produced and then
2 There must be a
constant supply of
caloric to make up
for what is carried
off by the containing surrounding
bodies vessel. Then
3. There must be
another supply of
caloric to convert
the water into steam
But the quantity of
caloric absorbed by
a given weight of
water when converted
into steam is much
greater than the
quantity of caloric
absorbed by a given
the same weight of
air when expanded to
twice its bulk.
In the Flash Pump
the Chamber need
not be all of a piece
it may be of thin
lead or copper or it
be well supported
with brick work.
The strength will
only be in proportion
to the quantity of
water in height:
i: if a fluid in
an state.
it will not increase
with the diameter
of the flash-chamber
The Chamber
must certainly be
strong - but this only
at bottom: and
the strength even
be given by arch
work, or by the
ground where circumstances
admitt
of its being built
low enough
Nor need the strength
be for a greater
part of the height
than that to which
the water will be
raised
Suppose 1/2 the
utmost quantity of
the air that can be
driven out and
32 foot the height
to which the water
could rise if the
whole of the air were
driven out: - the
16 foot is the
utmost of the waters
rise by a single flash
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Identifier: | JB/106/013/002 "JB/" can not be assigned to a declared number type with value 106.
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1793-12 |
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106 |
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013 |
flash-pump |
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002 |
flash & steam engine |
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text sheet |
2 |
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recto |
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jeremy bentham |
[[watermarks::[w with crown] [lion motif]]] |
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34601 |
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