DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.1401#0239
THE ILLUSTRATED EXHIBITOR.
187
that if a pressure of one pound per square inch be applied on the surface of the smaller piston, and the piston
of the larger cylinder present a surface ten times greater, the power is increased in the proportion of ten to
one; besides which, the lever-power used in applying the pressure to the smaller piston is obtained. The cylinders
are fitted with valves, so arranged as to prevent the return of the water from the larger to the smaller while the appa-
ratus is in action; and thus the power is accumulated in the former. In the instance before us, the two three-inch
cylinders already described in the proving-frame, took the place of the larger cylinder of the ordinary apparatus and
they were connected with the forcing-pump by a strong metal tube. As every girder was tested with a certain 'fixed
amount of pressure, an arrangement was necessary to ascertain where this had been reached. For this purpose an iron
cylinder, 1| inches in diameter, was placed in communication with the pipe connecting the pump and the press • so
that the pressure obtained in it was, in proportion to its diameter, the same as that in the large cylinder, and it' was
fitted with a piston-rod working in a vertical direction. This piston-rod was connected with a lever, from the end of
which a scale-pan was suspended at a distance from the fulcrum ten times greater than that of the point of attachment
of the piston from the same. The weight of the scale-pan and lever were balanced by a large mass of iron at the other
end. On the scale-pan a certain weight was placed, proportioned to the proof desired to be obtained, and the action of
the pump was continued until the water, rising in the iron cylinder just described, forced up the lever, and with it the
weight attached; and thus indicated that the pressure, to which it was desired to subject the girder, had been reached.
The weight to be placed in the scale-pan was thus determined : the diameter of the lever-cylinder being \\ inches, and
that of each one in the proving-frame 3 inches ; the pistons or " rams " in the latter presented together eight times the
surface of that in the lever cylinder, which, being multiplied by the difference of length of the two parts of the lever,
determines the weight of the scale-pan to be one-eightieth of that to which it was desired to prove the girder.
When a girder had been fixed in the frame for proving, the force-pump was Avorked till the pistons underneath the
girder carried it off its lower bearings and pressed it upwards against the shoulders of the upright standards, by which
it was firmly held, and the pressure was then continued until the amount previously fixed upon as necessary for proof
had been obtained. The ordinary gallery girders were tested in this manner with a pressure equivalent to a weight of
fifteen tons; but it was calculated that when fixed, the g-reatcst weight they would have to sustain would be seven-and-a-
half tons. In one instance, for the
sake of experiment, the pressure
was continued beyond the proof-
weight of fifteen tons, to see
what amount of strain the girder
would bear without actual frac-
ture, and it was found that a
strain of thirty tons produced no
visibly injurious effect; but the
girder broke in many places with
an additional weight of half-a-ton.
Every girder, as well as all
the other castings, were weighed
immediately on their arrival at
the works, and the girders proved
as just described ; in doing which
considerable assistance was de-
rived from one of Henderson's
Patent Derrick Cranes, which was
erected near the proving appara-
tus. By its means a girder was
raised from the wagon in which
it arrived, placed on the weigh-
ing-machine, weighed, removed
to the proving-press, tested, raised again, and deposited on the ground in a stack in less than four minutes. "We give
a general view of this machine, but must reserve the detailed description for a future number.
VIEW OF CRANE AND PROVING-PRESS.
•trfta ntt il)t tot (felniitfiuit-
BY M. BLANQTJI, MEMBER OF THE INSTITUTE OF FRANCE.
The first impression created upon the mind of the spec-
tator on beholding this magnificent structure, erected
with almost miraculous rapidity, is that of marvel at its
grandeur, simplicity, and elegance. All the proportions
are maintained with consummate art, and with mathe-
matical precision.
The horizontal measure of 24 English feet was taken as
the unit of the building, every horizontal dimension of
which is either a certain number of times or divisions of
24 feet. For instance, were it required to elevate any part,
two pieces of 24 feet were placed one on the other, and thus
a height of 48 feet was obtained ; and in the same manner
a height of 72 feet is reached by the addition of another
piece of 24 feet. The same as to length or breadth, which
is always a multiple of 24. The result has been the forma-
tion of a symmetrical palace, constructed of pieces of cast-
iron of equal length, fastened together with iron bolts,
and nearly all cast after the same pattern, or, as we should
say m political economy, of the same standard. Should it
be tound necessary some day to pull down this edifice, it
may be taken to pieces, and rebuilt elsewhere without any
change.
The building consists of an immense nave, transversely
intersected by a shorter one called the transept, of a height
sufficient to enclose trees of venerable growth in perfect
preservation, producing a most charming effect. _ An upper
gallery, approached by numerous and commodious stair-
cases, runs along the whole of the building. From this
point I was enabled fully to enjoy the magnificent spectacle
of the opening ceremony, at which there were present
more than 20,000 persons, most of whom were arrayed
in the most elegant attire. The English papers will not
fail to give you the details of this splendid solemnity, to
the eclat of which our organs and organists greatly con-
tributed. It was truly a noble and most imposing
spectacle.
Previous to entering upon my feeble labours with regard
to this great Exhibition, I must give you a general outline
of the manner in which the different nations are classed in
the respective places allotted to them. England has re-
187
that if a pressure of one pound per square inch be applied on the surface of the smaller piston, and the piston
of the larger cylinder present a surface ten times greater, the power is increased in the proportion of ten to
one; besides which, the lever-power used in applying the pressure to the smaller piston is obtained. The cylinders
are fitted with valves, so arranged as to prevent the return of the water from the larger to the smaller while the appa-
ratus is in action; and thus the power is accumulated in the former. In the instance before us, the two three-inch
cylinders already described in the proving-frame, took the place of the larger cylinder of the ordinary apparatus and
they were connected with the forcing-pump by a strong metal tube. As every girder was tested with a certain 'fixed
amount of pressure, an arrangement was necessary to ascertain where this had been reached. For this purpose an iron
cylinder, 1| inches in diameter, was placed in communication with the pipe connecting the pump and the press • so
that the pressure obtained in it was, in proportion to its diameter, the same as that in the large cylinder, and it' was
fitted with a piston-rod working in a vertical direction. This piston-rod was connected with a lever, from the end of
which a scale-pan was suspended at a distance from the fulcrum ten times greater than that of the point of attachment
of the piston from the same. The weight of the scale-pan and lever were balanced by a large mass of iron at the other
end. On the scale-pan a certain weight was placed, proportioned to the proof desired to be obtained, and the action of
the pump was continued until the water, rising in the iron cylinder just described, forced up the lever, and with it the
weight attached; and thus indicated that the pressure, to which it was desired to subject the girder, had been reached.
The weight to be placed in the scale-pan was thus determined : the diameter of the lever-cylinder being \\ inches, and
that of each one in the proving-frame 3 inches ; the pistons or " rams " in the latter presented together eight times the
surface of that in the lever cylinder, which, being multiplied by the difference of length of the two parts of the lever,
determines the weight of the scale-pan to be one-eightieth of that to which it was desired to prove the girder.
When a girder had been fixed in the frame for proving, the force-pump was Avorked till the pistons underneath the
girder carried it off its lower bearings and pressed it upwards against the shoulders of the upright standards, by which
it was firmly held, and the pressure was then continued until the amount previously fixed upon as necessary for proof
had been obtained. The ordinary gallery girders were tested in this manner with a pressure equivalent to a weight of
fifteen tons; but it was calculated that when fixed, the g-reatcst weight they would have to sustain would be seven-and-a-
half tons. In one instance, for the
sake of experiment, the pressure
was continued beyond the proof-
weight of fifteen tons, to see
what amount of strain the girder
would bear without actual frac-
ture, and it was found that a
strain of thirty tons produced no
visibly injurious effect; but the
girder broke in many places with
an additional weight of half-a-ton.
Every girder, as well as all
the other castings, were weighed
immediately on their arrival at
the works, and the girders proved
as just described ; in doing which
considerable assistance was de-
rived from one of Henderson's
Patent Derrick Cranes, which was
erected near the proving appara-
tus. By its means a girder was
raised from the wagon in which
it arrived, placed on the weigh-
ing-machine, weighed, removed
to the proving-press, tested, raised again, and deposited on the ground in a stack in less than four minutes. "We give
a general view of this machine, but must reserve the detailed description for a future number.
VIEW OF CRANE AND PROVING-PRESS.
•trfta ntt il)t tot (felniitfiuit-
BY M. BLANQTJI, MEMBER OF THE INSTITUTE OF FRANCE.
The first impression created upon the mind of the spec-
tator on beholding this magnificent structure, erected
with almost miraculous rapidity, is that of marvel at its
grandeur, simplicity, and elegance. All the proportions
are maintained with consummate art, and with mathe-
matical precision.
The horizontal measure of 24 English feet was taken as
the unit of the building, every horizontal dimension of
which is either a certain number of times or divisions of
24 feet. For instance, were it required to elevate any part,
two pieces of 24 feet were placed one on the other, and thus
a height of 48 feet was obtained ; and in the same manner
a height of 72 feet is reached by the addition of another
piece of 24 feet. The same as to length or breadth, which
is always a multiple of 24. The result has been the forma-
tion of a symmetrical palace, constructed of pieces of cast-
iron of equal length, fastened together with iron bolts,
and nearly all cast after the same pattern, or, as we should
say m political economy, of the same standard. Should it
be tound necessary some day to pull down this edifice, it
may be taken to pieces, and rebuilt elsewhere without any
change.
The building consists of an immense nave, transversely
intersected by a shorter one called the transept, of a height
sufficient to enclose trees of venerable growth in perfect
preservation, producing a most charming effect. _ An upper
gallery, approached by numerous and commodious stair-
cases, runs along the whole of the building. From this
point I was enabled fully to enjoy the magnificent spectacle
of the opening ceremony, at which there were present
more than 20,000 persons, most of whom were arrayed
in the most elegant attire. The English papers will not
fail to give you the details of this splendid solemnity, to
the eclat of which our organs and organists greatly con-
tributed. It was truly a noble and most imposing
spectacle.
Previous to entering upon my feeble labours with regard
to this great Exhibition, I must give you a general outline
of the manner in which the different nations are classed in
the respective places allotted to them. England has re-