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317 house of God; and it was a circumstance virtue; and a powerful encourager of inof peculiar gratification to learn, that dustry, frugality, and temperance-virmore than three hundred of these young tues so important to individual character persons were communicants at one of the and comfort, and to the general welfare churches in that town. The congregat- of society. ing of such vast numbers of young people
HENRY COLMAN. removed in general from the restraints of home, presents, it cannot be denied, great perils to virtue. The manufacturing districts of old countries have long been stig- Sir,- In a contemporary journal, there matised as places of most flagrant licen
appears a violent tirade against the tionsness and immorality. The character word gradient, as at present used amongst of our population is essentially different civil engineers; and a facetious atfrom that of the places referred to. Our ma- tempt is made by assigning to it an Hinufacturing population have in general had bernian origin, to drive it out of our vocathe advantages of careful domestic train. bulary by the force of ridicule; it is ivg, and a good school education. They moreover called barbarous; said to be are not manufacturers for life; but de
misapplied, &c. &c., all which joined to sign to remain only long enough in the the late introduction, or invention of the mills to get the means of a settlement word clivity, adopted in the translation of in life. They have undoubtedly, the Navier seems to challenge a discussion greater part of them in New England, of the comparative merits of the two been blessed with a religious education ; words. and they are looking forward to rise in
Gradient is derived, if I mistake not, life, and feel the high worth and indis
from the Latin gradus, a step, and is, pensable importance of character every
therefore, not inapıly applied to express where among us. These circumstances
“ the character of a road throughout its cannot fail to operate most favourably entire length taken step by step," as it among them; and their beneficial effects
comprehends all kinds of surfaces both are instantly to be seen. Whether they hilly and level; but clivity being plainly will remain sufficient will be inatter of deduced from clivis, a hili, is, though a just concern with every benevolent mind.
good general term for ascents, and deMuch is done likewise for their intel..
scent by no means applicable to levels, or lectual improvement. Frequent and most
any thing approximating thereto. valuable courses of scientific lectures are given,- to which access is made easy by
Again, in a note in the same pubthe payment of a very small see. A social
lication, there are some remarks on the library and reading room are established
use of the wori terminus, which I think likewise, on the most liberal principles perfectly, absurd. Beginning and end and a chemical laboratory and a splendid
cannot be properly applied to the termineralogical cabinet have been procured.
mination of a road, for people will comWe hare never been in a community
mence their journeys at which ever point
best suits their convenience. I think it where the spirit of inquiry seemed more active, or found more patronage and en
would puzzle the writer to determine
which is the commencement of the railway couragement. Add to all this, that great instrument
between Liverpool and Manchester. of virtue, of comfort, and of the amelio- Perhaps it would be well to substitute ration of the condition of the poorer and the plain English word termination for Jabouring classes, the savings' bank is the Latin terminus; but it is surely better in full operation among them; and here, to retain a correct word through a dead as in every case where it has been tried, language, than to displace it only to has produced the inost salıtary effects;
make room for an incorrect one in our the deposits ainount 10 200,000 dollars, own, the unsuitableness of which, would and promise to be greatly extended-a un that very account, be the more easily great proportion of the depositors being and generally detected. found among the young women engaged I should not have troubled you with in the establishments. The perfect se- these observations but for the dogmatical, curity of the wages of labour, is among dictatorial style of the article alluded to, the most efficacious protections of human which appears besides in a work that pro
CAPTAIN S. BROWN'S METALLIC LIGHTHOUSES.
fesses to give lectures on precision in scientific terms. Your obedient servant,
Q. Briggs. July 7, 1836,
CAPTAIN S. BROWN'S METALLIC LIGHT.
(From the Scotsman.) It has been proposed to place a lighthouse on the Wolf Rock, near Land's End, a position where it would be exposed to the most violent storms of the Atlantic; and a plan was drawn up for the purpose by Mr. Stevenson, who holds a high rank in this department of engineering ; which plan, Mr. Brown thinks, would require fifteen years for its execution, and cost 150,0001. Mr. Brown undertakes to erect one of bronze, 90 feet high, which would answer the purpose as well as the stone one of 134 feet, for 15,0001., and to complete it in four months. Lighthouses are generally of masonry, the outer stones clamped with iron, and in large blocks, to lessen the number of joints. The one on the Eddystone Rock, near Plymouth, erected by the celebrated Smeaton, is 24 feet in diameter at the base, and 90 feet in height, of which 72 consists of solid masonry. That built by Mr. Stevenson on the Bell Rock, near Arbroath, is 40 feet in diameter at the base, and 110 feet height, of which 102 consists of solid masonry. The defects of such a structure are obvious. In the first place, it consists of some thousand pieces; and, among as many thousand joints in it, a few faulty ones would be fatal to its strength. Secondly, its great breadth presents an enormous surface to the action of the winds and
Mr. Brown estimates, from experiments made by him at the extremity of Brighton Chain Pier in a heavy south-west gale, that the waves impinge, on a cylindrical surface 1 foot high and 1 foot in diameter, with a force equal to 80lbs.; to which must be added that of the wind, which, in a violent storm, exerts a pressure of 40lbs. He computes the collective impetus of the wave on the lower part of Mr. Stevenson's proposed lighthouse for the Wolf Rock, of the surf on the upper part, and of the wind on the whole, to be equal to 100 tons. On the bronze column of 90 feet, which Mr. Brown proposed to substitute for the stone structure, the pressure, calculated in the same way, would be only 6. tons. The natural height of the wave in a storm is supposed not to exceed 18 or 20 feet; but the surf, which is, we suppose, half water and half spray, rises, at times, above the head of the Eddystone column, hooding the lantern in a watery coat, and sometimes extinguishing the lights.
It unfortunately happens, that adding to the height of the column scarcely produces any greater security to the lights; for, as the breadth must be increased with the elevation, the surf, instead of splitting and passing off by the sides, as it would do upon a smaller column, just mounts so much higher, having a greater surface to resist its onward movement. At the Bell Rock, which is not exposed to such heavy seas as the Eddystone, the surf in a storm mounts to the lights, which are 100 feet above the ordinary level of the sea.
At such times, the column is felt to tremble when struck by the huge mass of rolling waters; and the keepers, perched like two sea-mews on the top of a beacon-staff, with nothing but the raging elements around them on all sides, feel their situation (as they confess) very forlorn, and naturally think of the sins of their past life.
Mr. Brown's proposed metallic lighthouse is 90 feet high, 14 feet in diameter at the bottom, and 4 feet at the thinnest part. The lower half, called the base, is in four pieces, each piece consisting of a portion of a hollow cone (or paraboloid), wider below than above, and about 10 feet high; the lower piece is sunk 3 feet into the rock, and is fourteen feet in diameter at its under margin; the fourth piece is six feet in diameter at top. These four pieces fit into each other, the neck of the lower passing into the socket of the upper, and both being secured by flanges; so that the joints are, in some degree, stronger than the entire part of the shaft. Above these is the smaller part of the slıaft, which is in three pieces of nearly the same length, and fitted in the same
Above this, the shaft widens out into an inverted cone, which forms one piece, and supports the more important parts. These are, first, the keeper's house, which is 8 feet in diameter, and 7 feet high, with a gallery round it," for look-out, and walking exercise.” Next the lantern 9 feet wide and 10 feet high to the cupola, for containing the lights. The house, or sitting-room, is made of two concentric cylinders of sheet copper, 9 inches asunder, to equalise the temperature, and attached to each other by rivets : it is formed into compartments for bookcases, shelves, and lockers, with a recess for the back of the stove. Immediately below the house, in the swell of the shaft, are the sleeping-berths. To complete the description of the column, we shall add, that the upper section of the base contains two tanks, one for oil, and one for fresh water; the next section, above, is for coals and provisions; and the one above that, a general store. Access is obtained from below by the chain ladder reaching down to the sea ; and by ladders in the inside, by which the keepers mount to their aerial abode. The whole 319
CAPTAIN S. BROWN'S METALLIC LIGHTHOUSES.
work, 90 feet high, would cost 16,0001. or 17,0001., if entirely of bronze ; 11,3001., if the base were bronze, and the upper part cast-iron; or 90001., if entirely of cast-iron ; and it would be erected in four months.
The advantages of this plan of Mr. Brown are the following :-1. The expense of erecting lighthouses is much diminished, so that six may be erected for the sum now spent on one. 2. The time necessary for building them is contracted from years to months; and the chances of loss of life in the progress of the work are proportionably diminished. 3. The bronze lighthouse, from the slenderless of its shaft, and the smallness of the resisting surface, will not carry the wave and spray half so high as the stone lighthouse; and, with two-thirds of the elevation, it will afford equal protection to the keepers and the lights. 4. From this slenderness, and its diminished height, the strain of tbe surge and winds upon it, in a storm, will not exceed one-tenth of what a stone structure is exposed to. 5. It has but eight joints from the bottom to the lantern; while the stone lighthouse has thousands; and the bronze joints admit of being made as strong as the entire part of the shaft. 6. That its separate portions, being complete circles, cast solid, each is, per se, capable of resisting any lateral impulse of the water whatever, and the column can only be injured by a transverse pressure operating upon its length. 7. That the cohesion of the materials, or the power of the column to resist fracture by a transverse strain, is probably a hundred times as great as in an equal column of stone. 8. That the natural stability of a bronze column, derived from downward pressure, must be considerably greater than that of stone. In addition to this source of strength, the column is to be secured 10 feet into the rock by numerous bolts ; so that it cannot be removed, without carrying all that body of rock along with it, which would require a pressure of several hundred tons.
As to the durability of bronze in water, when proper precautions are adopted, two letters are given from Mr. Brande and Mr. Faraday, which remove every reasonable doubt. Both of them think that cast-iron might answer sufficiently well for the upper part of the column. Nothing is said about the chances of injury from lightning ; but the tower, being entirely metallic, it would act, we suppose, as a very perfect conductor, and convey the electricity to the earth without injury to the keepers. Bronze is an alloy of copper and tin. We should have observed that, in Mr. Brown's opinion, a bronze column could be erected on a sand-bank, by piling, or by a different process, which he describes, and where a stone structure would be impracticable.
The situation of the keepers in one of Mr. Brown's lighthouses is one of the most singular which the multifarious occupations of human life present. The stone tower, though really less secure, has an appearance of solidity, which goes some length to satisfy the imagination ; but Mr. Brown's watchmen are suspended in mid-air, on the top of the pillar, whose slenderness, compared with its length, reduces it to the appearance of a small rod. Cooped up in a cage, one half of whose narrow floor projects over the sea, or standing on a gallery which hangs over it completely, they live for months together without exchanging words or thoughts with their fellow mortals. There they pass the dark and stormy nights, with the winds howling, and sea birds shrieking around them, while the abyss foams and rages below, and the slender stem that bears them above it quivers under their feet when struck by the angry surge, or beaten by the tempest. No situation can be conceived more dismal and monotonous, more beset with terrifying cir. cumstances, or better calculated to impress the mind with a constant feeling of insecurity. Such, however, is the force of habit in reconciling men to outward circumstances, which appal at first sight, and to real and formidable dangers too, that there is never any want of candidates for the most hazardous employments; and no difficulty is, we believe, apprehended in getting sober con. siderate persons to commit themselves to these sea-girt aerial cradles ; nor any doubt felt, that, after a month's experience they will sleep secure in them, though lullabied by storms and tempests, the aspect of which, in such a situation, would drive a greenhorn landsman mad.
To understand the importance of lighthouses, it may be proper to state, that the number of British vessels shipwrecked annually is about 550, or one and a half per day. The average burden per ship of the mercantile navy is about 110 tons; and, if we value old and new together at half the price of building, or 51. 10s. per ton, we have 6001. for the value of each, and 330,0001. for that of the whole ; which may be reduced to 300,0001. by deducting the value of sails, masts, and other materials, saved from some of those stranded. If we add an equal sum for the value of the cargoes, the whole loss from shipwrecks will be 600,0001. per annum. This statement proceeds on an old estimate from 1793 to 1829; but Mr. Maculloch says, in the Supplement to his Dictionary, that the number of ships lost, or driven on shore, in 1833, was no less than 800. It is probable, then, that the annual loss by shipwreck is not much short of a million sterling. If one-fifth part of this loss could be prevented by additional lighthouses, the saving in 320
which, as moved by a horse, opens the furrow, drops (at proper intervals, and in an exact and suitable quantity.) the corn, covers it, and levels the earth, so as, in fact, to plant the corn as rapidly as a horse can draw a plough over the ground. The inventor thinks it will save the labour of eight men. He is about to make some alterations in it to adapt it to the planting of cotton.-New York Paper.
Dr. Arnott's New Stoves.-At a meeting of the Philosophical Society of Edinburgh, which took place lately, one of Dr. Arnott's new stoves was exhibited. It is an oblong box, about three feet long, two broad, and two deep, carefully made air. tight on every side. A partition within divides it into two parts, apertures above and below enabling them to communicate with each other. An apei ture is arranged for the free adınission of air, and another for carrying off the smoke; an air-tight door admits fuel. A stove made of earthenware, and placed on one side of the partition, contains all the fuel required, and the hot air circulates round and round the partition before it is eventually carried off by the small tubular chimney. An extensive surface of 32 square feet is this presented to the air at a moderate elevation of tenperature, about 212 ; and accordingly, scajcely any thing passes up the chimney which has not heen almost entirely exhausted of its heat. This store saves equally time, trouble, and fuel, and is quite free from the dust of a common fire.
Dr. Reid's System of Ventilation -At the conclusion of the same meeting, the Society adjou ned to a new apartment, constructed by Dr. Reid, illus. trative of his arrangements for ventilation, &c. It is 32 feet long, and 18 broad, the floor being pierced with 50,000 apertures for the admission of air. А series of experiments have since been commenced in it, in one of which, intended to show the working of the tlues, 100 individuals remained in it for upwards of an hour, the room having been alter. nately tilled with warın and cold air, and partially charged with ether and nitrous oxide, at different times. The air was completely renewed by a slow and insensible current every five minutes, and the various changes so gradua ly induced, that it was iin possible to tell when they commenced. The plan is equally applicable to public buildings and private dwelling-louses, as well as to hospitals, churches, public assemblies, and all those places where, from a crowded apartment, the air becomes oppressive both from heat and noxious etfluvia. Scotsman.
The Supplement to Vol. XXIV., containing Ti. tle, Contents, Index, &c., and embellished with a Portrait of Mr. Walter Hancock, C.E., is now published, priec 6d. Also the Volume complete in boards, price 98.6d.
NOTES AND NOTICES.
money would amount to a million in five years, to say nothing of the still more important saving in human life.
NOTES AND NOTICES. T'elegraph - A new telegraphic system, applicable to nantical purposes, invented by M. Claude Sala, has just been presented as laying claim to thie Monthyon prize. It is described as remarkable for its simplicity; for, by the aid of eight signs, it produces, without difficulty, all the words of the vocabulary, and, by means of two lanterns, it can carry on a nightly correspondence.- Atheneum.
Arsenic.-M. Schweiger Seidel has invented a very simple method of ascertaining the presence of arsenic in food, &c. however sinall the quantity may be. He puts a portion of the inatter to be tried, and double its weight of soda, into a little glass tube; he closes the open extremity of the tube with blotting paper, and heals the other end with a tapar: the arsenic is sublimated in a few moments, and adheres to the sides of the tube in the part which is not leated.-Ibid,
Spontaneous Combustion.-An instance of spontaneous combustion is reported in the French papers, to have taken place at Aunay, in the department of Avalon. A very fat woman, aged 74 years, and addicted to drinking brandy at 27 degrees, lived alone, and one evening reinrned home as usual, but, as she did not appear among her neighbours the next inorning, they knocked at her door. No answer being returned to repeated demands, they summoned the mayor, who forced the door, and exposed a horrible spectacle, accompanied by an ex. traordinary smell. Near the chimney laid a heaja of something burnt to cinders, at one end of which was a head, a neck, the upper part of a body, and one arm. At the other end were some of the lower parts, and one leg, still retaining a very clean shoe and stocking. No other traces of fire were to be seen, except a blue fame which played along the surface of a long train of grease, or serous liquor, which had been produced by the combustion oi the body. The mayor found it impossible to extinguish this flame, and suinmoned all the authorities; and, from the state of the apartinent and comparison of circumstances, it was concluded among them, that previous to going to bed, for which she had evi. dently been making preparations, the woman bad been irying to ignite some e:nbers with her breath.. The fire communicating with the body by means of the breath, combustion probably took place, and wonld appear to coofirm an opinion entertained by several learned men, that that which is called spon. taneous combustion of the human frame never takes place without the presence of some ignited body near the person predisposed to combustion, A surgeon who bled an habitually drunken person, accidentally put the blood extracted near a candle, when immediately a blue flame appeared on the surface, which he found extremely difficult to extinguigh.
M. Biot.--The learned and scientific M. Biot has been delivering some very remarkable lectures at. the College de France. He has proved, that, by ine:ins of polarised rays, it is possible to ascertain the chemical action which takes place between bodies held in solution, in various liquids; an ac. tion which has not yet been discovered by less de. licate means. This is a new branch of science, created as it were by this great natural philosophier, from which the most important and curious results may be expected.
Corn and Cotton-Planting Machine. A frec man of colour, Henry Blair by name, has invented a machine called the corn-planter, which is now exhibiting in the capital of Washington. It is de. scribed as a very simple and ingenious machine,
De British and Foreign Patents taken out with economy and despatch; Specifications, Dis. claimers, and Amendments, prepared or revised ; Çaveats entered ; and generally erery Branch of Patent Business promptly transacted.
LONDON: Published by J. CUNNINGHAM, at
the Mechanics' Magazine Office, No. 1, Peterbo.