Kingdom.] RAILWAY AND MARINE MECHANISM. 231
North Areas A. B. 10 to 34; C. D. E. 1 to 10, & 19 to 33 ; F. 1 to 32 ; Gr. H. 1 to 13, & 19 to 26.
deflection in eight minutes increased to 1 '85 inches, whenit became permanent after sustaining the load during thewhole of the night, a period of about 16 hours.
“ On 9th November the experiments were resumed as
follows:—
Weight of
Deflection at the
Weight of
Deflection at the
Cargo in
point of the Jib
Cargo inTons.
point of the Jib
Tons.
in Inches.
in Inches.
11
2*05
16
3*00
12
2*22
17
3-20
13
2-40
18
3*50
14
2*60
19
3* 73
15
2-80
20
3-97
On again turning the crane
round with a load of 20 tons
there was no perceptible alteration in the deflection, andthe permanent set, after removing the load, was • 64 inches.
“ From the above experiments, it appears that the ulti-mate strength of the crane is much greater than is requi-site either in theory or practice, and, although testedwith nearly a double load, it is still far short of its ultimatepowers of resistance, which it will be observed are fivetimes greater than the weight it is intended to bear.
“ The advantages claimed for this construction are itsgreat security, and the facility with which bulky andheavy bodies can be raised to the very top of the jib,without failure. It moreover exhibits when heavily
loaded, the same restorative principle of elasticitystrikingly exemplified in the wrought-iron tubular girder.These constructions, although different in form, arenevertheless the same in principle, and undoubtedlyfollow the same law as regards elasticity and their powersof resistance to fracture.”]
Description of the annexed engraving of the Keyhamtubular crane:—
Fig. 1 is a side view of the crane, with a portion ofthe side removed to the foot, in order to show tirecast-iron cylinders built in the masonry, the rollerswhich encircle the body of the crane and support thestem vertically, with its rollers and bearings actingagainst the interior recess of the large circular platea a, between the plate and the frame, which embracesthe crane in a ring which contains the rollers, giving arotatory motion to the crane in any direction. Imme-diately above the rollers, is a platform of 12 feet in diame-ter attached to the stem, on which the men stand to workthe crane. This platform also enables a man, by turninga handle, to move the crane round in any directionat pleasure.
Fig 2 is a section of the body of the crane taken abovethe quay wall. The cells are carried along the concaveside of the jib, where they terminate in two cells nearthe top, and also in two cells near the bottom, wherethe stem enters the cast-iron shoe already described.
FIVE-TON TUBULAR CRANEOS SCALE
SIDE VIEW
418
The Devonshire Great Consolidated CopperMining Company, 17 Barge Yard ChambersProducer. , ^ nP V|
Models of two water-wheels, of 140-horse voje, each,erected at the mines of the above Company, lor the pupose of pumping water from the one shaft by P 3 t ’
and from the other by a drawing lift. Scale 1 ithe foot. „ . ;
1. Model of a wheel, 40 feet in diameter, by 12 teet mbreast, pumping from tlie depth of 115 fathoms,feet, with 14-inch pumps, 7 feet 6 inches stroke, dischaiging 60 gallons of water per stroke, andlifting ^ at •Stroke 69,000 lbs., the average velocity being 4aj strokel>er minute.
This wheel works a line of 3J inch round iron rods,390 fathoms or 2,340 feet; not exhibited on the scale ofthe model of the wheel, for the want of space, over pul-leys, ascending a hill, at an elevation from the wheel tothe shaft of 384 feet above the wheel.
This wheel pumps the water from the mine called“ Wheal Josiah.”
2. Model of a wheel 40 feet in diameter, by 12 feetin breast, pumping water from a depth of 80 fathoms; 60fathoms, or 360 feet, with 12-inch pumps; and 20 fathoms,or 120 feet, with 20 -inch pumps, of 6 feet stroke, dis-charging 98 gallons of water per stroke ; it lifts at eachstroke 40,600 lbs.
This wheel works a line of rods of 3j inch round iron