of these scas is, that the vessel will be able to proceed during a calm, the period at whith other vessels are in the greatest danger of being beset with ice. How far the machinery of a steam vessel may be worked in seas incumbered with ice, we are unable to form an opinion.* 1 ART. XXIII. On the new British Method of preparing Flax and Hemp. TH HE method which has lately been introduced in England, of preparing flax and hemp by the dry process, has of late excited considerable interest, not only in this country but on the Continent, and some remarks have appeared upon it in Les Archives Philosophiques et Litéraires, which call for a reply. It is there stated with truth, that Mr. Lee obtained the King's letters patent for his process, the particulars of which were kept secret by orders of Government (meaning, no doubt, by the Act of Parliament which was passed for that particular purpose); and that Messrs. Hill and Bundy have since obtained a patent for another process, affirmed to be preferable to Mr. Lee's, and that Government have also forbid its publication; so much do they believe it to be the interest of England to enjoy, exclusively, the process, the results of which are of such great importance to European industry. It goes on to state, that the French Government, which suffers nothing to escape that can contribute to the national In the article we have quoted, the non-existence of land in a northerly direction in the part termed Baffin's Bay, and to the north of Behring's Straits, is nearly taken for granted; Captain Burney has maintained, (and upon grounds which are scarcely touched in the Quarterly Review), that there exists a portion of land north of Behring's Straits, and which he supposes unites Asia with America. With respect to the formation of ice in the polar seas, it will be seen from the paper of Mr. Scoresby on this subject, that he is at issue with the writer in the Quartely Review; and if the fact of the formation of ice independant of land is once admitted, all probability of the polar seas being so free of ice as to be navigable, is removed. It seems absurd to us to expect any benefit in a commercial point of view, from a diminution of the distance to China by the discovery of a northern passage, when the difficulty which must attend such a voyage is considered. prosperity, ordered researches on this subject to be undertaken at the Conservatoire Royal des Arts et Metiers; and that M. Christian, the director of that establishment, although debarred from any information as to the English mode of procedure, had effected a very simple machine, consisting of rollers fluted longitudinally, and certain other apparatus, which is briefly described, and which was found to answer most perfectly the purpose for which it was intended. We therefore feel ourselves called upon to state, that the lastnamed patent was taken out by Mr. Bundy only, instead of Messrs. Hill and Bundy; and that this patent was enrolled in the usual way, without any Act of Parliament, interference of Government, or attempt at secrecy. On the contrary, the machinery was publicly exhibited and explained by Mr. Millington more than once, in his Lectures at the Royal Institution, before very numerous assemblies, as will appear by reference to the account of his Lectures in the last Number; and it has since been shewn and explained, both by the proprietors and by Mr. Millington, to several foreigners of distinction, and, in fact, to every person who was desirous of information on the subject. Mr. Bundy also obtained a French patent, and enrolled his drawings at Paris, very soon after the English patent was granted, for the protection of his particular and individual interest; but surely this ought not to be construed into any wish, on behalf of the English nation, to keep that to themselves which can be useful to the world at large. We understand that the Queen has adopted the use of these machines at Frogmore with perfect satisfaction, and that by their means she keeps 40 poor persons constantly at work. This is a meritorious example, worthy to be followed by every opulent landholder; and we beg to refer our readers to the benefits likely to accrue to the nation from the encouragement of flax husbandry, as detailed in the Report and Evidence of the House of Commons, given in the present Number. The whole month of April is an advantageous time of the year for sowing flax and hemp seeds. 188 TO CORRESPONDENTS. Trinity College, Cambridge, 6 January, 1818. THE Editor thanks Professor Cumming for the following letter, which he communicated to Mr. Daniell, whose answer is annexed. DEAR SIR, In the last Number of the Journal of the Royal Institution, there is a paper by Mr. Daniell, which however ingenious in other respects, involves an error that appears to me fatal to his hypothesis. He supposes (page 38) that because the superficies of an octohedron is double that of a tetraedron, its solid content is likewise double; and that, since in the instance he has given, there are 44 spheres in the octohedron, and only 20 in the tetraedron, the specific gravity of the former solid should be greater than that of the latter, as containing more than double the number of particles under a double surface." I need not tell you that the surfaces of the solids have nothing to do with the matter, for the specific gravities of the solids will be as their weights directly, and their volumes inversely. If n be the number of spheres in the side of the equilateral triangle on which these solids are erected, the whole number of spheres in the octohedron will be to those in n n 66 the tetraedron, as (2 n2 + 1) is to 7. (h2+3n+2), which 6 when the number of spheres is indefinitely great, becomes the ratio of 4 to 1. The volumes of the solids are to each other in the same ratio of 4 to 1; it follows then, that their specific gravities should be equal, and that Mr. Daniell's reasoning, so far as it is founded on mathematical considerations, is radically wrong. Were I personally acquainted with Mr. Daniell, I would have written to him; as I am not, you will, I hope, excuse my troubling you on this subject. I do this with the less reluctance, as I conclude you would wish rather to have the opportunity of correcting any mistakes that may appear in your Journal, than to allow them to remain till they are animadverted upon in any other publication. Believe me, dear Sir, truly yours, J. CUMMING. Mr. Daniell is much obliged to the Editor for Professor Cumming's friendly communication. He hastens to acknowledge and correct an error into which he has very carelessly fallen, and which materially affects the latter part of his second paper on the Elementary Construction of Crystals. He would, however, still venture to suggest, that an attentive consideration of the structure of a corner of a cube, as com→ piled of spherical atoms, upon the octohedral arrangement, would demonstrate the possibility of a different elementary arrangement in different parts of the same solid, and that consequently, equal weights may not necessarily be included under equal volumies. SIR, Letter from Dr. Prout to the Editor. I beg leave to correct an oversight in your late review of Dr. Thomson's Chemistry. In vol. 7, p. 111, of the Annals of Philosophy, you will find a second paper by me on the same subject as that you have quoted, in which several mistakes occurring in the first are corrected, and among others, one respecting ammonia. In this second paper, you will find that I agree with Dr. Thomson in considering ammonia as a compound of one atom of azote and three of hydrogen. I beg leave also to refer you to vol. iii. p.415, of the Royal Institution Journal, where you give an extract from a German paper, of which you appear to have thought favourably. The results there giveu coincide precisely with those I had long before published in the two papers above alluded to. I am, Sir, your's, &c. 8, Southampton Street, Bloomsbury, 23 January, 1818. W. PROUT. This communication of Dr. Prout materially strengthens our argument against hasty determinations of chemical equivalents and atoms, and sets in a striking point of view the danger of yielding to the facility of round numbers and numerical coincidences. It appears, upon making the reference above directed, that three months had not elapsed from the period of the publication of his paper before Dr. Prout found it necessary to publish "a correction of an oversight which influences some of the numbers given in his Essay," and to direct that some of the coincidences and round numbers should be "expunged." With respect to the oversight with which we are charged, we are not accountable for it; we merely referred to Dr. \ Prout's paper, as directed by Dr. Thomson, who unfortunately has forgotten to quote the corrections. MR. ELMES ON THE CONSTRUCTION OF PRISONS. February 2, 1818. SIR, In your last Number, Mr. J. C. Loudon has done me the honour of speaking of my late publication, "HINTS for the improvement of PRISONS," in terms of commendation, for which I here take leave to thank him :-but in his very outset he insinuates that his communication to you, is "in addition to the information" given to the public by me. to the facts, that I cannot suffer it to pass by unnoticed, as that part of the public who reads your very useful work, may perhaps never see mine, and unfair opinions of it and me, may be the results. This is so contrary Mr. Loudon next says, that his general plan, has the following" advantage, which is indeed its characteristic, that a prisoner may, during the whole time of his imprisonment, keep himself perfectly retired and unseen by any other prisoner, if he choose;" and of course this being " in addition to" mine, it is no part of my plans. In reply to this, I have only to request attention to page 16 of my work, where the third advantage of my system is fully stated to be that "from each prisoner having perfect seclusion from the rest, in the night, or whenever such seclusion may be desirable." So much for Mr. Loudon's" characteristic" being " in addition to" mine. Mr. Loudon then, most properly, exposes the defects of almost all the prisons and penitentiaries, both in England and |