« ZurückWeiter »
THE USEFUL ARTS,
From the history of scientific disco- ficiency of foreign intelligence, by a very, we are naturally led to detail more copious account of the inves
. the progress of the Useful Arts, that tions and discoveries which have been branch of knowledge which forms the made in our own country, and by ex. closest alliance with the necessities tending our arrangements for obtain. and comforts of our species. In this ing articles of intelligence which have humble department of our work, we not appeared in any other work. cannot expect to witness those high Though the block-machinery at er efforts of the mind which are so Portsmouth was invented previous to frequently
displayed in the history of the year 1809, yet as no account of abstract science; but we shall fre- it has yet been given to the world, quently have occasion to notice some cept in one work which is newly pubof the finest specimens of mechanical lished, we shall present our readers genius, and to admire that unwearied with an account of the singular D?; exertion of talent among artists of chanical process by which ships every class, and that perseverance in blocks, of various kinds and sizes
, tracing, a principle of construction are prepared for the navy. The through all its applications, which machines by which this operations have contributed so much to abridge effected are perhaps the most splenmanual labour, to multiply the re- did and ingenious that have ever been sources of industry, and to add to erected in the whole world, and en: that enormous power which man al. title their inventor to a high rank ready, possesses over the material among the mechanics of the present world.
age. In the year 1802, a patent for Though the present state of the this invention was taken out by Mark continent is highly unfavourable to Joambard Brunel
, and, at the recomthe execution of this part of our plan, mendation of General Bentham, 80; we shall endeavour to supply the de vernment resolved to erect a set of
block-machines in the arsenal of of which is to form the outside of the Portsmouth. The machinery was blocks to the segment of a large cirset to work in 1804, and consists of cle. For this purpose, ten blocks 44 machines, driven by a steam-engine are fixed by their extreme ends beof 32 horse power. In order to con. tween the rims of two equal wheels vey some idea of these machines, and fastened upon the same axis. These of the effects which they produce, wheels are then made to move round we shall trace the whole process from with immense rapidity, so as to bring the rough timber to the finished the blocks successively against the block.
edge of a fixed gouge, which thus By means of four sawing machines, cuts them to their proper curvature. distinguished by the ingenuity of their A progressive motion is also given to con struction, viz, the straight cross- the gouge, in order to give the block cutt ing saw,—the circular cross-cut. its proper curvature in a direction at ting saw,—the reciprocating ripping right angles to the planes of the saw -and the circular ripping saw, wheels between which they are fixed. the timber is cut into parallelopipe. When one side of the blocks is thus dons of the proper size for the blocks. shaped, all the ten blocks, by an inThe blocks in this rude state are ta- stantaneous movement are turned a ken to the boring machines, of which quarter round, so as to expose ano. five are used for the purpose of bo- ther side to the gouge, which shapes ring a hole for the centre pin, and them as formerly, and in this way ano Eher at right angles to this, for the third and the fourth side are the commencement of the mortice, formed of the proper shape. Three which is to contain the sheave. From of these engines are used for blocks this machine, the blocks are carried of different sizes. to the morticing machine, of which The blocks are now taken to the three are used. This beautiful ma- scoring engine, which is intended to chine gives motion to several chiselsform the score or groove round the in a vertical direction, which mortice largest diameter, for the reception of out the cavities for the reception of the ropes or straps of the block. the sheaves. A chip as thick as a By these machines are formed the piece of pasteboard is cut with the shells of the blocks, which are polishmost wonderful accuracy, and these ed and finished by manual labour. chips are prevented from accumula. The next part of the operation is the ting, by means of a piece of steel at formation of the sheaves, which are the back of each chisel, which thrusts made of lignum vitæ. By means of them out. The chisels make from two saws, the straight saw and the 110 to 150 strokes every minute. circular saw, the tree of lignum vitæ When the necessary cavities are more is cut into pieces approaching to a ticed out, the blocks are taken to the circular shape, and nearly of the corner-saws, (of which there are thickness of the intended sheave. three,) by which all its angles are cut These pieces are carried to the crown off in succession, by means of a cir- or trepan saw, with a centre-bit in its cular saw mounted on a maundrel. axis. * When the piece of wood is
When the blocks are thus sawn properly, fixed, the saw is applied into a polygonal figure, they are care against the wood, and cuts it into a ried to the shaping enginc, the object circular form with great rapidity,
while it at the same time forms a hole iron pins; the polishing engine, for exactly in its centre.
polishing the iron pins; the machine The blocks are now taken to the for boring very large holes in any pa coaking engine, a machine remarkable sition, which is used for the largest for the ingenuity which it displays. sizes of blocks; and the machine for It is employed to form in the centre making dead eyes. of the sheave a cavity of the shape of No fewer than 200 sorts and size three small semicircles, arranged at of blocks are constantly making by equal intervals round the centre hole these machines, and more than 1420 formed by the crown saw. This ca. blocks are manufactured in the course vity is intended for the reception of of a single day. Such of our readers the coak, or metal bush, which is as may be induced by the preceding made of copper, zinc, and tin, and cast description to inquire further into of the same shape as the cavity now the subject, will find their curiosity formed. When the coaks are insert. amply gratified by consulting the are ed into the sheave, the drilling ma ticle BLOCK MACHINERY in the Edin. chine is employed to perforate the burgh Encyclopædia, which is the three semicircular projections of the first account that has been given of coaks and the wood beneath, in order that curious operation, and which is to fasten the coaks by copper pins illustrated with five perspective draw• put into these holes. The pins be- ings of the principal machines. ing placed in the holes then drilled, A new portable bridge has beea are rivetted by means of the rivetting invented by Mr James Elmes, Cheaphaminers, which are made to strike a side, London. Bridges of this conheavier blow at the end of the opera- struction may also be rendered partion.. The sheave is now carried to manent. A description and drawing the broaching engine, and fixed to an of this invention will be found in the axis revolving vertically. A broach Philosoph. Magazine, vol. 33, p. 12. or cutter is brought down into the A method of hastening the matohole in the centre of the coak, for the ration of grapes has been proposed by purpose of enlarging it, and making John Williams, Esq. For this purpose, it truly cylindrical. The sheaves are a ring of bark, from 1 to 2 eighths of then finished by the face-turning luthe, an inch wide, is cut from the trunk of which has a sliding rest that supports the vine, or from the smaller branches the turning tool, and moves it slowly when the trunk is large, so as just to across the face of the sheave. As expose the alburnum without injuring the face of the sheive which is thus it. The shoots which come from the turned is composed partly of the me- root of the vine, or from the front of tal coak, and partly of wood, and as the trunk, situated below the incisios, it has been found by experience that must be removed as soon as they apdifferent velocities are required for pear. In every case in which Mr turning wood and metal, the machine Williams tried this experiment
, he has a very ingenious contrivance for invariably found that the fruit not changing the velocity when the tool only ripened earlier, but that the berpasses from the wood to the metal. ries were considerably larger and more Besides the machines which we have highly favoured than usual
. M enumerated, there are other four; Williams supposes, that, by cutting viz. the turning lathe, for turning the through the corter and liber without
wounding the alburnum, the descent coat, and the third coat should be of of that portion of the sap which has oil-paint alone. The paint is made undergone preparation in the leaf is in the following manner :-To 96 obstructed, and confined to the branch- pounds of English ochre, ground in es above the incision, and that the boiled oil, are added 16 pounds of black fruit is thus better nourished and paint, being one-sixth in proportion brought earlier to maturity. Mr of the ocure ; this when mixed forms Williams supposes that this practice an indifferent black. The solution, may be extended to other fruits, but made of one pound of soap and six particularly to figs. The preceding pints of water, is to be added to this method furnishes an explanation of paint, and well united with it: and the well-known fact, that vineyards without the canvas being previously improve every year by age till they wet, this composition is to be laid are fifty years old, and that the fruit upon the canvas as stiff as can conveis brought sooner to maturity in old niently be done with the brush, and vines. For when the vines become this first coat will form a tolerably old, the rigidity of the vessels ob- smooth surface. The second coat is structs the circulation of the descend- to be formed of the same proportion ing sap, and thus produces the same of English ochre and black, without effect which is obtained by an exci. any soap solution, and the third or fi. sion of the bark. See the Transac- nishing coat must be done with black tions of the Horticultural Society, paint as usual. This method has met vol. i.
with such general approbation, that A method of painting linen cloth it is employed for all the canvas in in oil colours, so as to be more pliant, his Majesty's dock-yards, and produrable, and longer impervious to duces a saving of one guinea upon water than in the usual mode, has been every hundred yards of canvas which discovered by Mr William Anderson, is thus painted. master painter of his Majesty's dock The silver medal of the Society for yard, Portsmouth. The ingredient the Encouragement of Arts, Manufacwhich he employs is perfectly simple, tures, and Commerce, was voted to being a solution of yellow soap, and Mr Anderson for this invention. See the composition is thus made :-To the Transactions of the Society for one pound of soap is added six pints 1807 in the Philos. Magazine, vol. of water in a vessel over the fire ; in a xxxiii. p. 151. few minutes after the boiling of the A methodofraising large stonesthat water, the soap will dissolve ; whilst are deeply sunk in the earth has been hot, it is to be mixed with oil paint, invented by Mr Robert Richardson prepared as hereafter directed, and is of Keswick. This effect is produced then fit for immediate use. The by the power of a tackle of pullies above quantity of soap solution will combined with a windlass. The tackle be sufficient to mix with one hundred is fixed to the top of the stone by a weight of paint : the first coat to cylindrical iron plug, which is simply be laid upon the canvas must be en. driven into a cylindrical excavation tirely of this composition, without in the stone of the same shape ; the first wetting the canvas in the usual windlass is then turned, and so firmly way. A very small proportion of it, does the plug adhere to the stone, or none, is necessary in the second that it is immediately raised from the
ground, even when it is above four joining the horizontal wires qualifie
: tons in weight. It seems rather dif- every part of the length to bear the ficult to explain the cause of the firm highest degree of tension. This fence adhesion between the plug and the has been used at the royal pleasera stone, as the plug is driven into the grounds at Frogmore, and in variou opening merely by a few blows from parts by the nobility and gentry: a hammer ; but we imagine that it When three feet six inches high, it is arises partly from the great friction found sufficient to esclude the largest between the plug and the stone, and and strongest kinds of grazing stock. partly from the plug being pressed When raised to the height of fire more against one side of the cavity feet six inches, it is sufficient for parki than another. By this valuable in- containing deer, which have never yention, two men can raise as many been known to leap over it. Wha stones as twenty men could do in the it is employed to keep lambs out of
plantations, perpendicular wires conThe silver medal of the Society of paratively slight are interwoven upon Arts was voted to Mr Richardson for the lower horizontal ones. See Paz. this invention. A drawing and de. Magazine, vol. xxxii. p. 270. scription of the machine will be found An improved telegraph has been in the Transactions of the Society invented by Major Charles Machands for 1808.
of the island of Jersey. The object Mr James Pilton, Chelsea, has in. of this telegraph is intended to es: vented a new fence made of tort elas- press numbers which may be seen at tic wire, which becomes invisible at a distance, and to which words may a comparatively short distance, and is be referred at pleasure. The sur calculated for pleasure grounds. The ber of combinations may be carried main wires are drawn out to the thick. to forty thousand, which exceeds by ness of a common quill, and continu. many thousands all the words in the ous strings of these are inserted ho. English language. Words may then rizontally through upright iron stan. be forwarded as fast as they cao be chions. The interval between the looked for in a dictionary; and ever strings is about nine inches, and that whilst only an equal number of letters between the stanchions seven feet. could have been communicated by The horizontal wires, in a state of the present mode. Another advar tension, are fastened to two main tage arising from the use of words is stanchions at the extremity of the telegraphic communications is, that fence, passing at freedom through by words of the same meaning in diferholes drilled in the intermediate stan- ent languages having the same net chions. The tension of every hori. ber, correspondence may be carried zontal wire is preserved by the supe. on from one language into another, rior stability of the extreme stan- which, although not grammatically chions, on the construction of which, correct, would yet be sufficiently in. and the mechanism of the wire work, telligible. the resistance of the whole, as a bar. The silver medal of the Society of rier against heavy cattle, depends. Arts was voted for this invention, When the extent of the fence is great, See the Transactions of the Society the main stanchions are relieved at for 1808, in the Philos. Magazes expedient distances by other princi- vol. xxxiii. p. 348. pal stanchions. An improved mode of Thomas Andrew Knight, Esq.