FRENCH AND ENGLISH GUNPOWDER, &c. FRENCH AND ENGLISH GUNPOWDER. By a report lately made to the Minister of War in France, it appears that the best powder made in that country is composed as follows: In 100 parts 78.00 saltpetre, 12.88 charcoal, 9.12 sulphur. The best Dartford powder contains 79.70 salt petre, 12.48 charcoal, 7.82 sulphur. A litre of the former weighs 905 grammes, while a litre of the latter only weighs 857. The difference of density is occasioned by being subjected in the manufacture, to different degrees of pressure; and it is stated by the French chemists, that the more dense the powder, so as not to check the combustion, the better. The strength of the French powder of this density is considerably greater than English powder; but reduced to the same density they are nearly equal. But the French powder with which these experiments were made, was the patent powder of M. Bouchet; and prior to his improvements, the best powder in France, was 3-20ths less strong than that made in England. The comparison was made with Dartford powder; we believe, however, that à still stronger powder was for a short time made in England. 255 which he was supposed to have writ-. civil rights must keep pace with the ten the moment before he became general improvement of their minds; quite insensible, and to have been un- and as they rise in the scale of society, able to write in an intelligible form, they must acquire that commanding by the actual stupefaction of his fa- influence which their new relative culties. position is calculated to confer. As the people become more intelligent, they are less liable to be misled-superstitious errors loose their holdquackery is hooted out of cxistencethe power of demagogues is annihilated-mobs and tumults, occasioned by knavery working upon ignorance, are at an end--and as the great mass of society cannot be moved but when their rights and priviliges are in real danger, their union and zeal on such occasions must render their strength irresistible. The government of France does not entertain the same opinion on these subjects as we have above expressed, and therefore M. de Corbiere, the Minister of the interior, has, in his wisdom, suppressed all the schools of mutual instruction, which had been established by benevolent societies or individuals. But there is one institution, similar in its object, though not in its origin or regulations, to our Mechanical Institutes, which has been allowed still to exist-namely, the public lectures at the Conversatoire des Arts et Metiers. In the amphitheatre or lecture room of that establishment, a course of popular instruction is given in Political Economy, in Geometry, and Mechanical Philosophy applied to the Arts, and in Chemistry applied to manufactures. It is enough in praise of the manner in which these courses of lectures are conducted, to state, that the first is given by M. Say, one of the first political econoThe various mechanical institu- mists of Europe; the second by M.C. tions, which within these few years Dupin, the author of the Voyages en have been established in the different Grande Bretagne; and the third by great towns of this empire, have M. Clement, a well known practical justly attracted the attention and chemist. M. Dupin, whose publicamerited the applause of every en- tions we are always ready to welcome lightened patriot. These institutions with pleasure, and whose activity of promise in a short time to better, mind is such that he seldom allows materially, the condition, and to in the public long to forget him, has just crease the power, of the labouring published his introductory discourse classes. Nor is their political vigi- to this year's prelections. Like all lance likely to be lessened by augmenting their intellectual and moral strength. Their knowledge of their POPULAR INSTRUCTION. the other productions of the same author, this little work is distinguished by extent of inforination, elegance 256 POPULAR INSTRUCTION, &C. of diction, and liberality of views. from her mines? No: she has no M. Dupin is calculated to be a great mines which produce gold. Did she benefactor to his countrymen, by in- extort it from conquered nations in troducing among them a knowledge her transmarine possessions? Never of those mechanical arts in which we did India or America, by their tribare their superiors-by explaining to utes or spoils, enrich the public treathem the causes of our superiority- sury of Great Britian. What then in by boldly informing them of the in all times has been the source of her stances in which they must yield the riches? The industry of her people, palm to their neighbours-by con- and the labour which is its element. verting their feelings of narrow jea- We must admit that 14,000,000 of lousy into a sentiment of generous ri- English and Scotch possess greater valship-in short, by liberalizing as industry, and produce more commowell as instructing their minds, with dities, than 30,000.000 or 40,000,000 regard to the scientific progress and of the nations of the continent. This mechanical improvements of other is the reason why 14,000,000 of Scotch nations. M. Dupin reasons strongly and English have been able to strugin favour of instructing the industrious gle with advantage during peace and portion of society, and enforces his war against more numerous adversaarguments by a reference to the state ries. Far from us be those vain deof knowledge among English and clamations of writers and orators, Scotch mechanics, and the advanta- who sacrifice truth to popularity in ges derived from it in the improve our assemblies, our saloons, and our ment of the arts. "I will tell those workshops-who tell us perpetually men," says he, "who see nothing but of our superiority-who perpetually mere machines in the laborious ring in our ears. that we are the first classes, that I know a machine more people on earth. Doubtless we have powerful than that of Watt-more every thing requisite to become so; ingenious than that of Arkwright, but at the present moment, far from and greatly more susceptible of im- being in the first rank, I fear we are provement. The whole universe far, far distanced by England. Engdoes not contain twenty thousand of land has arrived at a remarkable Watt's machines, nor ten thousand of epoch, which prepares for her new those of Arkwright; but the kind of destinies, and greater prosperity than machine to which I allude is multi- she has ever before attained in peace plied on the face of the globe a thou- or war. sand million of times. The steam We hear that M. Dupin has been engines of the whole world do not made a Baron, and a Member of the represent a force greater than that Legion of Honour, by the new king. of four hundred thousand horses; We hope that the liberality as well and I know one which represents the as the talent of his publication. had force of one hundred million of horses! its due weight in procuring for their What then is this machine? Must I author these honorary distinctions. mention it in adopting the degrading language of some persons? It is man. We shall not enter farther into this ingenious and liberal paper than by citing the following passage: London Mechanic's Register. Among the present exhibitions at Paris, is that of a human fossil which was found near Moret, in the department of the Seine and Marne. In abusing England, we have sometimes heard it affirmed that she gained her victories by her treasures, which subsidized nations against us, rather than by the valour of her own defenders. But, in the first place, Communications for the American this is to avow that gold is even mi- Mechanics' Magazine, post paid, and litary force; and how did England addressed to J. V Seaman, Newacquire this gold? Did she draw it York, will receive due attention. To the Editor of the Mechanics' roads, it way be expected that the Register. 50 BROAD-STREET. SIR, Amidst the eagerness with which the public are rushing forward to form plans for establishing communications by means of rail-roads, the old conveyance by canals is al most forgotten; and, indeed, from the prospect of gain and celerity displayed by the projectors of these aid of water will soon be discarded. The proprietors of some canals, although much disposed to be supine, have I believe begun to take the alarm; and probably all will become alive to their danger, when bills are presented to the House of Commons for forming rail-roads; acting as is too often the case, for the defence of their own property, by opposing the plans of the incipient speculators. ROTATIVE SCULLING WHEELS. 259 Judging from the liberal spirit lately river, it appears to be ill adapted to displayed by parliament, I am incli- continuing the motion or resisting the ned to suspect that they will not al- waves which dash against the vessel. low private interest to arrest the Thus impressed with the necessity of march of improvement, but that they improving the method of propelling will permit rail-roads to be attempt vessels by steam, I was much gratied in all directions, even if obviously fied by receiving an invitation to be in the way of older establishments, present at the exhibition of a new leaving it to the efforts of the compe- and improved mode, by way of extitors to prove with which plan the periment, on a sheet of water in the superiority rests. grounds of Charles Gordon, Esq. of Presuming then that the canal Dulwich Hill, This experiment. proprietors will be compelled to conducted by the inventor, who is sustain a competition, I wish to sug- in the employ of Messrs. Gordons, at gest to them a mode by which their Deptford, I had lately the pleasure movements, more fit for the torpor of of witnessing; and the result was so past ages than the enterprise of the satisfactory, that I am anxious to dipresent period, may be accelerated; rect the attention of engineers in and as they do possess some advan- particular to it. The velocity and tages over their opponents, the sug- steadiness of the motion so far exgestion which I am about to make ceeded that of the same model when may, if properly applied, preserve impelled by paddle wheels moved by for them a superiority, which other- the same spring which worked the wise they could not maintain. new contrivance, that I could not doubt of its superiority; and the stillness of the surrounding water was such as to give to the vessel the appearance of being moved by some magical power. In a comparative experiment made by the ingenious and modest inventor, and frequently repeated, it appeared that the velocities of the model, impelled according to the old mode and the new spring, by the same was as seventeen to twenty. It is not necessary here to remark, that the use of steam constitutes the distinguishing feature of modern improvements. This power has in some degree superseded the use of wind in navigation, and of wind and water as the prime movers of machinery. It is now nearly ready to supersede the use of horses upon our roads; at least hydrogen, one of the constituents of steam, is about to do so; and if it be not also found in place of horses as the impeller of barges Before describing the sketch which upon our canals, inland navigation I have transmitted with this letter, I must soon be discarded. To drag will insert the account of his plan several barges in succession by a which I received from the inventor. steam boat, is a plan which I have no doubt has occurred to many when thinking upon this subject; but the inconvenience of the paddle wheels According to your request, I send generally used. and especially the you my remarks on the Rotative Sculling injury done by them and the agitated Wheels for propelling vessels. First, I water to the banks, which are neces- would notice their compactness, in not sarily very near to the barge, have occupying more than one fourth part of appeared insuperable difficulties. In the space the common wheels do. general steam navigation, I have al- seen in the plan, they may lay in ways considered the paddle wheel the most imperfect and objectionable part of the arrangement. The manner in which it strikes the water is attended with loss of power; it is dangerous if approached by small boats, on account of the swell which it occasions; and in a stormy sea or To Dr. Birkbeck Honoured Sir, As harbour with other vessels, without any danger of being injured at all, which is at present a great inconveniency. Secondly, the superior advantage in a rough sea, in which they act the same as in a calm pool, being entirely beneath, in the solid, dense water; and besides, their weight, from their situation, as will plainly appear, will be as ballast hold an object at sea |