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Sailors, like landsmen, who form opinions of the operations of

.nature, from mere casual and superficial observation, without conde

scending to look into causes and effects, must of course very often come to erroneous and ridiculous conclusions. Witness the following anecdote which occurred to me :

The boatswain told one of the passengers that the stormy petrels, or Mother Cary’s Chickens, make no nest, but lay two white eggs on

_the water, and then take them under their wings to hatch them ;

during this time the male bird supplies the female with food!

This fable is, I believe, current among the lower class of seamen.

On telling this story, however, the chief qflicer laughed very heartily, and cautioned me not to receive as gospel every “ yarn the boatswain chose to -spin ;" but lo ! in a very few minutes, he told me as truth, a story which appeared to me fully as marvellous as the other : He said, that in some of the islands to the southward, and about Cape Horn, there is a bird called the “ King Penguin," which had a pouch between its legs, into which it puts its egg, (for the Penguin only lays one,) as soon as laid ; in this pouch the egg is kept for 24 hours, during which time the female remains on shore, but at the expiration of that time, the male bird, who is also furnished with a similar pouch, returns from his fishing excursions, and relieves the female by receiving the egg into his custody for the next 24 hours. -They take a very long time to shift this egg from one pouch to the other, and although there are several species of Penguin on those islands none of them are furnished with a “ patent egg-boiler," save his majesty the King Penguin of the Southern Isles !!

He added, that the bird may be induced to drop the egg, although reluctantly, by running a stick between its legs ll

Having offered these remarks, I shall proceed in my next, to give you an extract from my Journal, kept on the voyage, in which I noted down every circumstance connected with Natural History, and which being written not from memory, but from facts at the moment occurring, may perhaps be considered worthy of perusal.

Since writing the above, I have had an opportunity of perusing Gn1FF1'rn’s Translation of Cuvmn, and find, that the Booby is stated to be the “ Pelecanns Sula;” the plumage is thus described : “ Belly and vent, all white, when young, all brown l" this is rather a meagre description, but nevertheless proves, that the Booby is not an Albatross, as supposed by the writer in Loudon’s Nat. Hist.

V.--Roof qf the New Iron Foundery at Kdsipur near Calcutta.

We have requested Major Hurcnmson of the Engineers, the architect of this elegant structure, to favour us with drawings of its various details, that we may make known, as far as the circulation of our journal permits, his very successful combination of the cast-iron truss with a wrought-iron tie to roofs of large span in this country. We are so little accustomed to see any thing else in India but the heavy fiat roof with its rnassy timbers groaning under an inordinate load of terrace-work heaped up most disadvantageously in the centre to allow a slope for the water to run ofl’, while the invisible white ant is scooping out the solidity of the timber, and the dry rot is corroding the ends that support the whole on the wall,——that the eye rests with quite a pleasurable sensation on the view of a light, airy frame-work

like that before us, composed of materials indestructible, wherein the i

strains and pressures are connterpoised, the load lightened, the liability to crack and leak lessened, and the repair of every part rendered easy and entirely independent of the rest.

The progress of improvement is notoriously slower in Government operations than in private works. When cast-iron beams were first brought to India on private speculation, and were offered to Government by a mercantile house in this town, they were rejected. The roof of a large private godown was soon after constructed with them, and their efficacy thus proved; then immediately a re-action took place, and a large quantity was indented for by Government. The Hon’ble Court sent them out, and they have remained until now totally unemployed, although numerous public buildings have been erected since they arrived.

It was, we know, a subject of lengthened debate what sort of roof should be given to the foundery. A timber trussed roof had been sanctioned at 15,000 rupees, and we may, perhaps, rather attribute the substitution of the present one to the numerical reduction of the pecuniary estimate, than to any actual conviction of its superiority in other respects, for the beams being already provided, the whole cost of the present roof, exclusive of them, has been only rupees 11,000.

The New Foundery, or rather the room in which the cannon are turned and bored, is a spacious hall, of 169} feet long by 50 feet clear span in breadth, and 40 feet in height from the floor to the vertex of the roof ; entirely open from end to end, lighted by a range of upper windows, and surrounded by a suite of apartments of half elevation. The steam

machinery of the several borers and lathes, is arranged along one side _

of this room, in a compact and exceedingly neat manner. It is impossible

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for turning the trunnions :—-the crane carriage for the guns, 8:0.

The self-acting principle by which the exterior of the gun~__is turned, while the interior is bored, so as to’. save one half of the time,; while it ensures perfect concéntricity of -t-he»onter and inner circles, _is, we be- _ lieve, an'_ invention of Major Hu'roa1Nson’s, who took- the opportunity when on furlough, of visiting some of the principal‘ founderies in Europe, and studied to adopt every improvement suggested ,b‘y,their inspection. 'I ; ,' - ‘,1

‘The whole'appa-r'atu's-is-driven b_yTa small engine of; 10 horse power, which also works a circular, and arreciprocating, saw,‘a_nd a loarn-mill for thelcasting-rnoulds.of the fonndery. , \~;1;

The s'uperficial;ar-ea of the_hall.is. 8462 square feet; to form an idea of,this' magnitude,; may'.be mentioned that the noble edifice of the new Town Hall in Birmingham, is said to contain a larger space than any room i1'i',-Eiirope; 'and' will accommodate between three and four thousand person_s=sitting,' ortenthousand standing ; that room is 1719, feet long, by '85; feet‘ broad, -making‘ a superficial area of 91-00 feet-,;§ which is only'6‘38,~feet m0'retthan"th'e'K§.sipur apartment. ' i

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Thereof consists of '10 trusses, Plate VI. Fig. 1, each composed a pair of cast-iron 'bean\_1s ‘pitched ' at an elevation of 12-21 feet in the; vertex, and tied together. at foot by a horizontal chain supported in-tile; centre \_by. a vertical rod suspended from the angle. The truss-frames are 15 feet 4.6 inches apart: they support light cross-beams and rafters of wood, upon which the planking of the roof is nailed. The weight of one truss with its entire load and chain, is equal to about fi,v_e'a_hd half tons, diffused over the two iron beams. ' The chain is three inches deep by one inch thick; ".2 3 inehéfi in section, consequently the applicable ~force of tension of thechain is 3x9 = 27 tons, and the ultimate strength of it 3x 27 = Sltons. The above weight of five and half tons-:difl'_used over the two -beams, = 2% tons‘ on each beam, gives according.-to the sine of theangle of elevation; aitension on the chains of -about_-five and half tons; or only one-fif.th:.tlie‘strétching weight, or one-fifteenth of the ultiinatestrength

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