Sidebilder
PDF
ePub

British plants on the authority of the stock of British animals. We Ray, who mistook a variety of the shall mention the principal. cinerarea integrifolia for a hieracium. The cancer or crab genus compreA new species of hieracium, the ce- hends a considerable number of sperinthoides, has been found in the cies. Mr Montagu has described the Highlands of Scotland by Mr Don. following, most of them not previous

Various additions have beeen made ly known to occur upon our shores. to zoology, both British and foreign, They were chiefly found on the coast the most remarkable of which we shall of Devonshire. Cancer foridus, tu. here notice. It will not be expected, mefactus, denticulatus, astocus subhowever, that we should notice the terraneus, astocus stellatus, astocus different systematic works which have multipes, astocus gibbosus, gammaappeared in different countries during rus locusta, gammarus pulex, gammathe period to which our history ex- rus saltator, gammarus littoreus, gamtends: these must unavoidably be in marus grossimanus, gammarus talpa, a great measure compilations. gammarus rubricatus, gammarus fal

Mr Kirby, who had already distin- catus; in all 15 species. He has guished himself by several valuable likewise described the following spepapers on insects, has published a cies of phalangium and oniscus. Phadescription of a new genus of insects, langium spinosum and aculeatum ; to which the name of Apion has been oniscus testudo, gracilis, thoracicus, given. He has described 61 species; and squillarum. He has also descri. most, though not all, of which are bed several species of British molus. natives of Britain. Several of them ca, a tribe of sea-animals that have are quite new. Most of these insects not been so much studied as they dehad been previously arranged under serve. The following are those which the genus curculio of Linnæus, or the he has described : Bulla hydatis. attelabus of Fabricius. Mr Kirby This is a very singular animal, not re. has shewn that they possess a well. ferable to any class in the Systema marked generic character.

Naturæ. Doris longecornis and noMr Marcham, well known for his dosa; Aphorodita clava; Amphitrite valuable writings on insects, has pub- infundibulum ; Terebella tentacula ; lished an account of a new genus of Nereis pinnigera ; Halothuria peninsects from New Holland, to which tactes ; and Lucernaria auricula. Of he has given the name of Notoclea. most of these animals he has given He has described and given figures figures. of 20 species. These insects, how- It has been generally believed that ever, are not absolutely new. They there are two species of the vespertilio are described in Latreille’s Genera ferrum equinum, or horse-shoe bat, difCrustaceorum, et Insectorum, publish-fering chiefly in size. But the smaller ed at Paris in 1807, under the name species has been seldom seen, and by of Coccinalloides.

some has been reckoned merely a vaColonel Montagu, one of the most riety. Mr Montagu has found both distinguished and indefatigable of the of these species together in the south British zoological writers, and well of England, and has ascertained them known by his ornithological diction. to be quite distinct. He has publishary and other valuable works, has ed a description of both, confining made several important additions to the trivial name ferrum equinum to the large species, and calling the account of this bird, who described smaller vespertilio minutus. He like it under the name of Sylvia Provinwise discovered the vespertilio barbas- cialis, and affirmed that it was accustellus in Devonshire. It was known tomed to conceal itself among cab. to exist in France, but had not been bages from its enemy the bat. Mr suspected in England previous to his Montagu has discovered likewise, that discovery.

the following birds are natives of The birds described under the England : Ardea Æquinoctialis, litnames of falco cyaneus and falco py- tle white heron; Tantalus Viridis, gargus, and called in English hen. green ibis ; Scolopax Noveboracenharrier and ringtail, had been suspect- cis, red-breasted snipe ; Glancola ed to be only the male and female of Austriaca, Austrian pratincole. the same species ; but the conjecture These are the principal additions had not been verified, and on that that have been made to British zooaccount they had been described by logy. Some animals from the East naturalists as distinct. Mr Montagu Indies and South Sea islands have been has at last decided the point, and as- likewise figured and described; as, for certained that the birds constitute example, two new species of Didel. only one species, the hen-harrier being phis from Van Diemens Island, by Mr the male and the ringtail the female. Harris, and the Ursus Indicus, or InA servant of the Rev. Mr Vaughan dian Badge, by Colonel Hardwicke. found a nest of these birds, contain- Such are the principal improveing three young ones and an addle ments that have been made in Cheegg. They were brought up by Mr mistry, Botany, and Zoology, during Montagu till their sex and plumage the period to which our history exwere distinct, and the result was the tends. In the other departments of discovery above mentioned.

science the improvements have been Mr Montagu has found the sylvin less striking ; we may therefore, with. Dart fordiensis, or Dartford warbler, out any breach of propriety, reserve in England, and has corrected some our account of them for the scientific mistakes committed by Buffon in his department of our succeeding volume. HISTORY

OF

THE USEFUL ARTS,

FOR 1809,

From the history of scientific disco- ficiency of foreign intelligence, by ą very, we are naturally led to detail more copious account of the inventhe 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 obtainand 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, ex. 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 mecxertion 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 operation is 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 enthat 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, go. 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 construction, viz. the straight cross- the gouge, in order to give the block cutting 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 another 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 ihree are used. This beautiful ma- scoring engine, which is intended to chine gives motion to several chisels form 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 mor. is cut into pieces approaching to a ticed out, the blocks are taken to the circular shape, and nearly of the corner-sarus, (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 car. 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 pocoaking engine, a mamine 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 sizes three small semicircles, arranged at of blocks are constantly making by cqual 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 ar. 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 been are rivetted by means of the rivetting invented by Mr James Elmes, Cheap: hammers, which are made to strike a side, London. Bridges of this con. heavier blow at the end of the opera. struction may also be rendered per. tion. 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 matuhole in the centre of the coak, for the ration of grapes

has been proposed by purpose of enlarging it, and making John Williams, Esq. Forthis purpose, it truly cylindrical. The sheaves are a ring of bark, from 1 to 2 eighths of then finished by the face-turning lathe, 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 sheave 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 incision, 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 flavoured than usual. Mr enumerated, there are other four; Williams supposes, that, by cutting viz. the turning lathe, for turning the through the cortex and liber without

« ForrigeFortsett »