At the end of autumn the tree has completed its vegetation; the sap and peculiar juices no longer exist in it as such, but are changed into wood and other solid matter, and in consequence are not so much disposed to decomposition as they were when in a state of fluidity; the water is nearly gone, and the wood, as if so designed by Nature, is fit for cutting, being in a state of suspended animation, which state, I supposemay be prolonged by cutting off the sources of future vivification. I have noticed Elm trees which were cut down in the spring, germinating the succeeding spring, and, on rending away part of the bark, have found the sap in circulation; had these trees been cut and converted to use, I have no doubt that instead of finding a branch, I should have seen a fungus. From the above, I draw the conclusion, that spring is an improper time to fell timber, and that its being loaded with juices disposes it to a hasty decay. It will be objected to the plan of cutting timber in the autumn and winter, that the bark will be ruined. It has been proved that trees will continue to grow and flourish when deprived of a great part of that covering; it will be of no injurious consequence to the tree, then, to strip it of its bark at the most convenient time, and suffer the tree to remain until autumn to complete its vegetation*, taking care to envelop the trunk with hay or straw bands, so as to defend the sap vessels from the sun and wind. But, even supposing that the growth of the tree should be affected by these means, yet it will be the external zone alone that will suffer; and that is of but trifling consequence, as, in the conversion of timber for shipping especially, that part is cut away. By these means, then, timber may be procured free from sap and the peculiar juices, to which fluids the fungus owes its origin; for, upon analysis of it, I found it yielded most of the principle of which they are composedf: procure timber free from these two fluids, and fungus will be prevented. * The practice of barking trees in the spring, and felling them in the winter, is of ancient date: it was recommended in 1687 by Dr. Plott to king James the second, and by him referred to the consideration of the Admiralty and Navy Boards. † Analysis of Fungus.-To the decoction I added; At the end of autumn a small portion of water will remain in the tree, and, in conveying it to the various places at which it is to be used, more will necessarily be absorbed. To expel this, and to season the timber, the logs should be first sided, or cut out into their different qulifications, and then placed in sheds constructed for that purpose, of large capacity, and with sides of swinging loover-boards; in these must be placed stoves, the funnels of which should run through the whole length of the building, and be capable of raising their atmosphere to a temperature between 90° and 100°, when some of the loover boards are canted to admit a current of air; those to windward should be canted below, and those to the leeward aloft; care must be taken that the current of air be not very rapid. By adopting this method, the water may be totally expelled in a few weeks, and the timber may then be removed to other buildings of the same construction, but without stovest; and thus timber in a short time may be rendered fit for use, well seasoned, and of greater durability and strength than that at present used. To diminish the heat of the atmosphere on shipboard, and in buildings, is the next consideration. The method for ships that are laid up in harbour, and for buildings, is, to open channels for the free circulation of air into all parts of them. For ships in employ, let a number of conical holes be made, so that their bases shall open immediately below the lower deck (in ships of war called the gun-deck), and the summit of the cone rise as it approaches the outside, so as to make it of as great a height above the water-line as possible. To 1. Solution of nitrate of silver, precipitated bitter principle. 2. Do. Gelatine Do. Tannin. 3. Infusion of galls Do. Gluten. 4. Muriate of alumine Do. Extractive. 5. From the Spirituous tincture, water precipitated Resin. 6. Evaporated the spirtuous tincture, residuum Resin. It is indispensible to keep timber dry at all times for its preservation, as exposing it in stacks to the rain and sun is the sure means of its destruction. I have known thousands of loads of timber to be ruined for want of the above precaution. these holes solid cones of oak should be fitted, be wound round with oakum, and smeared with tallow, and then driven in hard. On each side of the conical hole a strong staple being fixed, and the solid cone furnished with an iron face and knob, a strong bolt passed through the staples, and over the knob, would effectually secure it in its place. In fair weather, the cones being withdrawn, and the holes being in number about twenty, equidistant fore and aft on both sides, an abundance of fresh air would be poured in through them into the lower parts of the ship. Large trunks might also be passed down the stem and stern; and a communication being opened fore and aft in the hold, that part of the ship, which is now the residence of noxious vapours and heated air, would by these means be rendered cool and wholesome; and these might be kept open at all times, being furnished with a hood to prevent the rain and sea passing down them. One of the tubes at each end of the ship should be considerably shorter than the other, for the purpose of conveying away the heated air. Thus I presume, I have pointed out methods of obviating the causes of dryrot. RT. DADD. An Academy, in some measure similar to our society for the encouragement of Arts, has been recently estab lished at Vienna; it is endowed by the Emperor with his grand collection of Natural History, and likewise possesses an extensive chemical and philosophical laboratory, together with models and specimens of machinery, &c. The Austrians hope by its means to improve their manufactures, and to become independent of foreign industry. The design is potriotic, and we wish them success; but of this we are certain, that as foreign nations become rich by means of manufacture, so will a new class start up for the purchase of British manufactures. A country, merely agricultural, is never a very good customer.-[Edin. Mag. pavement has led to a further specimen in Spurr-street, Leicester-fields, and that there is little doubt but in a few years stone-pavements will be banished from our streets as clumsy and expensive, uneven and perishable.-Another great improvement has taken place in gas lights, in the introduction of pipes of Delft ware, which are a fifth of the expense of iron, and actually more durable. This reduction of expense will rapidly accelerate the general introduction of gas lights as well in London as in country towns. More than half London is now lighted by gas, but we have not an accurate list of provincial towns, in which it has been introduced. Miss A. M. PORTER, author of the Recluse of Norway, will soon publish the Knight of Saint John, a romance. Miss BENGER, is preparing for the press, Memoirs, with a selection from the Correspondence, and other unpublished Writings, of the late Mrs. Elizabeth Hamilton, authors of Letters on Education, Agrippina, &c. in two volumes, small octavo. SIR HUMPHREY DAVY states that flame is gaseous matter heated so highly as to be luminous, and that to a degree of temperature beyond the white beat of solid bodies, as is shown by the circumstance, that air not luminous will communicate this degree of heat. When an attempt is made to pass flame through a very fine mesh of wire-gauze at the common temperature, the gauze cools each portion of the elastic matter that passes through it, so as to reduce its temperature below that degree at which it is luminous, and the diminution of temperature must be proportional to the smallness of the mesh and the mass of the metal. Sir Humphrey Davy is at Paris. M. BUSCH, the learned traveller in Lapland, is there also. M. BIOT is in Scotland, to assist in the grand trigonometrical survey, &c. and to visit the Orcades. M. MUFFLING, charged by the king of Prussia with continuing the trigonometrical survey of the French engineers, is in France, for that purpose. Colonel MUDGE, charged with a similar labour by the Britsh government, bas invited several of the savans of France to cross the channel, and verify his operations. The baron CoCQUEBERT DE MONTBRET, known by his immense labours on the statistics of France, is gone to the southern departments to pursue the geological researches still wanting to complete the physical history of the kingdom. M. PREVOST, of Geneva, is on his way to England and Scotland. GERMANY. Animal Magnetism is at present in high repute in Germany, as a remedy in the cure of diseases. Many large works, and numberless pamphlets, have been written on this subject within two or three years, and even hospitals have been established, for the reception of such patients as require the aid of magnetism. A periodical work is publishing in Switzerland, by a society of veterinary practitioners, under the title, "Archives of Veterinary Medicine." Four numbers have already appeared. There is publishing in Hanover, by Crome, a Manual of Natural History for Agriculturists. It promises to be a very popular and useful work. Henriette Schubart has lately published, at Altenburg, a translation of Walter Scott's Scottish ballads and songs. There has lately appeared at Frankfort, by Dr Diels, a systematic work on the principal species, kinds, and varieties, of fruits cultivated in Germany. A little volume, entitled, Plurality of Worlds; or some remarks, Philosophical and Critical, in a Series of Letters, occasioned by Discourses on Christianity, viewed in connexion with the Modern Astronomy, as published by the Rev. Dr Chalmers, is in the press. Preparing for publication, in two large 8vo volumes, illustrated with maps, "An Introduction to the critical Study and Knowledge of the Holy Scriptures," by Mr. Horne, sub-librarian of the Surrey Institution. This Work, on which the author has been engaged for many years, will be divided into three parts. Part I. will contain a view of the Geography of the Holy Land, and of the Political, Religious, Moral, and Civil, State of the Jews, illustrating the principal Events recorded in the Scriptures. Part II. will treat on the various subsidiary means for ascertaining the sense of the Scripture-Figurative Language-The reconciling of the apparent contradictions of Scrip ture-Quotations from the Old Testament in the New, with New tables of all the Quotations-Applications of the Principles of Scripture-Interpretation to the Historical, Prophetical, Doctrinal, and Moral Parts of the Bible. Part III. will be appropriated to the Analysis of the Scriptures, comprising an account of Canon of the Old and New Testaments, together with Critical Prefaces and Synopes to each Book. A copious Appendix will be subjoined, containing an account of the principal MSS. and Editions of the Old and New Testaments-of various Readings, with a digest of the chief Rules for weighing and applying them-Rules for the better understanding of Hebraisms— Lists of Commentators, and Biblical Critics of eminence, with Bibliographical and Critical Notices of each, extracted from authentic sources; together with Chronological and other Tables, necessary to facilitate the study of the Bible. It is a peculiar feature of this Work, that references are made throughout to the most approved writers on every topic, in order to assist further researches, and thus render the volume a useful Manual to the Biblical Student and to Divines. Mr Accum has in the press, Chemical Amusements, comprising a series of curious and instructive Experiments in Chemistry, which are easily performed, and unattended with danger, An Account of the Origin, Progress, and Actual State of the War carried on between Spain and Spanish America, by a South American, is nearly ready for publication. A general history of the quadrupeds of America, illustrated by coloured plates engraved from original drawings, is preparing for publication. It will correspond in form with the late Alexander Wilson's splendid illustrations of American Ornithology. The ancient library of Heidelberg has been restored in great splendor, and now contains some of the most curious manuscripts in Europe. ERRATA.-Page 355, Art. II, for "Officer of the United States' army," read, Officer of the United States' Navy. |