Obrázky na stránke
[blocks in formation]

period. Besson taught philosophy and mathematics, with great reputation, at Orleans, and acquired celebrity as an ingenious mechanic, by the models of contrivances he exhibited in his lectures. But a more satisfactory record of his merit, than the applause of his contemporaries, remains in a collection of machines * hearing his name, which was published after his death by Beroaldus, in 1578. An anonymous tract, printed at Orleans during the author's lifetime, contains a good account of the expansion of water into vapour by heat. +

Great as was Besson's merit, it had a formidable rival in that of a contemporary; and the excellent Capitano Agostino Ramelli was more fortunate than he by reaping, in his lifetime, the honour due to his ingenuity. Educated at Rome, Ramelli cultivated ihe fine arts amid the bustle and active duties of a camp; and, as an engineer, united the taste and facility of an artist, with the judgment of an experienced artisan in his delineations of machinery. At the date of the appearance of his book, (1588) he was then an old man, living at Paris, on a pension from Henry III., into whose service he had entered at an early period, and repaying, by the benefit his labours had conferred on the country of his adoption, for the honour and affluence he owed to the patronage of its monarch. I

• Theatrum Instrumentorum et Machinarum Jacobi Bessoni cum Franc Beroaldns, figurarum declaratione demonstrativa. Lugduni, 1578.

+“ D’une mesure d'eau, par chaleur et atténuation ils s'en font dix d'air, qui tient une grande espace par dessus nous, au contraire par froideur ils s'en font de dix d'air une d'eau.' p. 25. L'Art et Science de trouver les Eaux. Orleans, 1569. Canini, a Venetian, in 1566, had also made some experiments on this subject.

Le diverse ed artificiose Machine del Capitano Agostino Ramelli dal Ponte della Trefia. Ingegniero Christianissimo Re di Francia et de Polonia. A Parigi, in casa del autore, 1588.

[blocks in formation]

Although this monument of the excellent Capitano's industry and ingenuity may contain nothing strictly entitling him to a notice, in a summary appropriated to a sketch of the progress of steamengine machinery, yet, as his and Besson's publications may be considered as the first mines whence machinists, throughout Europe, drew the materials of their general improvement, a notice of them can hardly be omitted in any subject of practical mechanics, connected with the period. Here may be observed many fine inventions, which, after having been long forgotten, have been again revived as new; while others have received im. provements, almost entitling their authors to claim the merit of original conception.

From the influence these works had on subsequent compilers, it must be regretted that at that time no good model of mechanical description existed to guide the labours of those whose taste or profession led them to describe machinery. The connection, arrangement, and use of the machines are given in these and later works with neatness and perspicuity,and the engravings, as diagrams, are excellent; but any thing relating to the velocities and proportions of their parts is seldom found. This, to the artisan, is a point of essential importance; the efficiency and durability of his handywork mainly depending on his knowledge of these particulars. This want of precision among practical writers, helped not a little also to prolong the reign of visionary speculation, on hypothetical combinations, in that class whose studies had a theoretical direction, and who found it more congenial to their natural indolence to indulge a fanciful genius, by giving the reins of their minds to imagination rather than to reason. Deduction from experiment was unknown to them ;


23 and the tact, which often supplies its place, but can be acquired from experience alone, was not theirs. Their mechanical chimeras, however visionary in themselves, might have passed as trifles, and been tolerated as harmless, because carrying evidence of their own absurdity; but they upfortunately had a deeply injurious tendency; being heedlessly considered as lights directing in the path of truth, instead of beacons warning against approach to a precipice of error, they not only produced disappointment, but distracted attention from things which ought to have been followed. The obstinacy with which this philosophical delusion was cherished, marked it as a vigorous shoot of that social Quixotism, whose influence still lingered in the usages, and tinctured the opinions, of society throughout Europe. The same aberration of intellect, which prompted romantic adventure in search of ideal perfection, made the alchymist of the period recklessly cast gold itself into the furnace, in the vain hope of finding among its ashes a talisman for its unlimited reproduction ; and mechanics, struck also with the mental pestilence, wasted that “precious stuff that life is inade of” in figuring machines, by which mountains could be raised by a child's breathing on small sails attached to a combination of wheels and pinions, and in pursuing the phantom of perpetual motion.*

* Decaus observes, that the multiplication of moving forces is so great, that had he a spot to place a machine on, (as Archimedes boasted,) he could move the earth. He is candid, however, and he says, “It has not yet been put in practice, because there are no such grea hts to move; and also that it would be difficult to get a foundation, and a machine strong and solid enough to support “ un si pesant fardeau” Raisons des Forces Mouvantes, p. 18.

The following quotations, although written long after the



It were, however, injustice to refuse to many, who were obstinate dreamers, the merit of sometimes, by accident, producing inventions of an useful and original character. Notwithstanding a belief in astrology, and a pursuit of alchymy, Baptista Porta, a Neapolitan gentleman, was an expert chymist, and an able mathematician and natural philosopher. His works carried the faine of his acquirements throughout Europe ; and, devoting his fortune, as well as leisure, to the advancement of science, his house became the centre of a society in which was to be found every

period alluded to, will give some idea of the extent to which these fancies were carried. They describe vagaries which flourished luxuriantly for centuries, and which are not yet decayed.

“Sampson could lift up the gates of a city on his shoulders ; and that the strongest bonds were but as flax burned with fire, and yet his hair being, shaved off, all his strength departed from him. By mechanical contrivances, it is easy to have made one of Sampson's hairs, that was shaved off, to have been of more strength than all of them when they were on. By the help of these arts, it is possible (as I shall demonstrate) for any man to lift up the greatest oaks with a straw, to pull it with a hair, or blow it with his breath." The whole apparatus of the engine that will do this, doth consist in two double pulleys, “twelve wheels and a sail." The roots of the oak he estimates to cover a surface of a thousand feet square, and forty feet deep, equal to four thousand millions of pounds weight; “ the proportion of the wheels being as ten to one each; if the weight of the straw or hair be equal to the hundreth part of a pound, it will be of sufficient force to pull up the oak; if the wheels and nuts (pinions) be proportioned as a hundred to one, then it is very evident that the same strength of a breath, (blown on small sails) or a hair, or a straw, will be able to move the world." In another part, supposing “ the first wheel to move four thousand turns in an hour, the world would be moved more than a hair's breadth in ten years;" and after a long calculation, “ it would not pass one inch in a million of years," saith Mersennus, with some exultation. Wilkins, Math. Mag. p. 34. See also Terra Machinis Mota, by Paulo Cassato, Roma, 1658, for some extraordinary illustrations.

[blocks in formation]

person distinguished for rank and acquirement in Naples. We owe the magic lantern to his ingenuity; and, in his commentary on the “ Pneumatica," (the last made among those in whose language it was first disseminated throughout Europe,) is found a beautiful extension of one of its most interesting propositions. The author, it is admitted, made no application of his apparatus as a mode of raising water, directly by the force of steam, from rivers and fountains; but his diagram and descriptions are so complete, that its application to this purpose by another, could not be considered even as a variation of his idea.

A retort, a, (fig. C,) has its neck inserted into the bottom of a vessel or cistern, c, which is nearly filled with water by the funnel e, and well closed; a pipe, i, goes through the cover. The water in the retort being heated, steam rises into the upper part of the cistern, and, by its expansion, expels the water it contains through the pipe i, inserted into its cover.


* “Faccisi una casa, c, di vetro è di stagno, e sia nel fondo busato, per dovi passi una canna di un'ain polla da distillare, che sia, a, e questa habbi una, o due oncie d'acqua dentro, e sia il collo saldato nell fondo della cassa, che non possa de la scorrer fuori. Dal fondo della cassa si parti un canale tanto lontano dall fondo quanto basti a scorrer l' acqua, e questo canale passi per lo coverchio fuori pocco lontano dalla sua snperficie. Questa cassa si riempi di acqua per il buso, e, e doi si ferri bene che non possa respirare. All ultimo ponerete la detta boccia sopra il fuoco et. andate scaldandola pian piano che solvendosi l'acqua in aria premerà l'acqua nella cassa e quella farà violenza all'acqua, che salisca per il canale, i, e ne scorra fuori. E cosi andare sempre scaldando l'acqua sinche sarà finita tutta : e mentre sfumerà l'acqua sempre l'aria premera l'acqua nel vaso e l'acqua uscirà sempre fuori.

“ Finita essalatione si misuri quant acqua sara fuor della cassa, che in luogo dell'acqua usita fuori vi sarà restata tant aqua.


« PredošláPokračovať »