DIFFERENCE OF LONGITUDE BETWEEN GREENWICH AND NEW YORK, 143 1. The coolness of the engine-room as aforesaid, and the preservation of the health of all occupied with the machinery, render it peculiarly suitable for voyages in warm climates. 2. The natural compactness or condensation of this coal (the steam-producing power being directly proportioned to its purity) will enable trading steamers to make longer voyages with the usual weight of fuel, or, in going their ordinary voyage, to make more room for stowage of the cargo. 3. To diminish the cost of fuel for steamnavigation by bringing into the market not not only the anthracite coal fields of Great Britain and Ireland, but also those of the United States. It will considerably diminish the cost and risk of a Transatlantic trip to be certain beforehand of finding in the port of New York a supply of anthracite from the Pennsylvanian collieries fully equal to our own. 4. In time of war the absence of smoke may be of the greatest moment in concealing the approach of an armed steamer, or rather in not betraying its existence as such to the enemy. If this exemption from cognizance as a craft possessing the power to DIFFERENCE OF LONGITUDE BETWEEN I have the satisfaction to inform you of a second instance of the successful transport of chronometers from London to New York, for the purpose of determining the longitude of these two cities. The first, as you will remember, took place in the months of July and August last. The result then obtained was compared with that given by M. Daussy, a distinguished French hydrographer, in the Connaissance des Tems. The difference of these results was 2.63 sec. This was satisfactory under the circumstances of a first attempt, made in the first trip across the Atlantic of the British Queen; still I felt the difference to be too great to be permitted to remain without an attempt to diminish it, or to ascertain which of the two was nearer the truth. On the very next voyage, therefore, of the same vessel, and under the same friendly auspices of Captain Roberts, and my friends in the United States, I sent a second set of four chronometers from London to New York. Their rates, &c., were ascertained precisely as those of the first set, and the whole experiment conducted in the same manner. This voyage of the British Queen was made, out and home, in the last and present months. The result, I have the pleasure to announce, is this time, almost exactly the same as that of M. Daussy's; so near, indeed, that I feel it to be a duty, and one of the most pleasing nature, to express thus publicly my great admiration of the accuracy of his statement : By this second experiment the h. m. sec. Hall, New York, is .... .4 56 0.24 W. According to M. Daussy it is 4 56 0.72 Difference of the two obser- This very minute variation in the estimates of the astronomical distance of two meridians so widely separated as those of London and New York, will be very gratifying to every lover of practical science both in France and England, the more so, when it is considered that these estimates were made independently of each other, "by different observers, in different years, and in vessels propelled by different agents." Perhaps it ought not to be omitted, that in both the English experiments the instruments were sent out unattended by any savant, and brought home their own report. During the first voyage there had been observed in all the chronometers, a difference between the mean travelling rate and the mean stationary rate, which had the remarkable character of being always on the same side, viz., the losing rates were always increased, and the gaining rates always diminished. The same curious fact again occurred in the second voyage. From this circumstance the longitude of New York was given by each chronometer scarcely enough to the westward in the outward-bound voyages, and rather too much so in the homeward ones. The great rapidity and accuracy with which this important branch of nautical inquiry may be pursued over the whole surface of the globe, as the agency of steam shall be extended, is now, I think, demonstrated. The instances under consideration show that observations may be made connecting very distant countries, and their several results compared in a few weeks-a circumstance of great consequence-for with the diminution of duration in a voyage, proceeds, in a higher degree, the diminution of all the chances and causes of error in chronometrical experiments at sea. Within the space of ninety-nine days, we have seen the British Queen carry chronometers four times across the Atlantic, and give ample time during each of her visits to New York for the necessary observations of rates, &c. All objections founded on the idea that the motion of a steam-vessel would affect injuriously the more delicate movement of the chronometer, and taint the results, must now fall to the ground. In the two voyages out and home of the British Queen, no derangement occurred, and the determination of the longitude of the far-distant ports she sailed between, is, probably, settled for ever, within the fraction of a second of the truth. I am, &c., ED. J. DENT. 84, Strand, 8th Nov., 1839. NOTES AND NOTICES. Weight of Blood in the Human Body.-The following account of the quantity of blood in the human frame at the different stages of existence, is given by Dr. Valentin on the Bulletin Général de Thérapeutique Médicale:-In the male subject, the blood at birth weighs 0.73 of a kilogramme (the kilogramme is 21b.); at one year, 2.29; at two years, 2.75; at three, 3.03; at four, 3.46; at five, 3.83; at six, 4.14; at seven, 4.62; at eight, 5.10; at nine, 5.52; at ten, 5.99; at eleven, 6.38; at twelve, 7.11; at thirteen, 8.10; at fourteen, 9.28; at fifteen, 10.64; at sixteen, 12.24; at seventeen, 13.16; at eighteen, 14.04; at nineteen, 14.52; at twenty, 14.90; at twenty-five, 15.66; at thirty, 15.80; at forty, 15.78; at fifty, 15.47; at sixty, 15.02; at seventy, 14.45; at eighty, 14.04.-In females, it is as follows: At birth, kilogramme, 0.59; at one year, 1.88; at two, 2.31; at three, 2.52; at four, 2.87; at five, 3.14; at six, 3.39; at seven, 3.74; at eight, 4.02; at nine, 4.55; at ten, 4.90; at eleven, 5.32; at twelve, 6.19; at thirteen, 7.03; at fourteen, 7.72; at fifteen, 8.37; at sixteen, 9.01; at seventeen, 9.95; at eighteen, 10,77; at twenty, 11.04; at twenty-five, 11.17: at thirty, 11.18; at forty, 11.49; at fifty, 11.85; at sixty, 11.50; at seventy, 10.89; at eighty, 10.45. The Seasons.-A writer in a late number of the Edinburgh Journal enters into an examination, from the comparison of meteorological records, of the prevailing opinion that the temperature of the weather, and indeed the general character of the seasons have sustained some remarkable changes in our island. He comes to the following, we think just conclusion upon the subject. "We thus see, by irrefragable evidence, that in these years, selected at random from the last century, there was the same mixed hot and cold weather as we now experiencethe summers abounding in cold disagreeable days, and the winter's cold interrupted by occasional mild weather. The conclusion to which every candid mind will arrive is, that it is in a great measure an erroneous conception, that the winters were so much colder and the summers so much warmer in past years than they are now. The reason, it seems to us, why the belief alluded to is entertained by people of advanced years, is simply, that the very hot years and very cold years which they have seen in the course of their lives, have left a strong impression on their minds, while all the others have been forgotten. Thus, on calling up their weather recollections, they find only a number of these re markable years engraven on their memories, and as the intervals are blank, they not unnaturally fill up the picture with tints of the same kind as those remembered." Mr. Joseph Strutt, of Derby, is about to give a further proof of the interest he takes in the welfare of the townsfolks of Derby-we might say of mankind. He has entrusted to Mr. Loudon, the celebrated author on gardening, the planting and arrangement of eleven acres of ground, which, when complete, are to be given to the public for the recreation of the increasing population of that industrious town. We hope such an example of generosity will meet with imitators. Ancient Inventions, &c.—“ Nautilus" writes us, in reference to Mr. Trevelyan's communication in No. 846, that "For the purpose of calling in question the originality of a description of an ancient fire engine, which was extracted into your pages from some old book, he adduces the same description in another old book; which, having been published only 12 years earlier, and in a closely neighbouring country, can only be looked upon as contemporary, neither being, most probably the original. But Mr. Trevelyan does not appear to be at all aware of the copious and most interesting exposition of the subject which was given by Mr. Baddeley, in number 798 of the Mechanic. Maga* Again, in another part of the same communication, Mr. Trevelyan repeats nearly the same words, with respect to planispheres, as had already appeared long before, in No. 824. There is one thing new, however, in his remarks upon the subject, when he declares that his planisphere, "manufactured by his Majesty's globe makers," is made exactly similar," to that described at page 70, vol. xxxi; if so, I must say, his Majesty's globe makers must have been very incompetent persons, as the description, so referred to, contains many glaring detects and misconstructions." zine. Improvements in Locomotives.-The following is a description of a new invention, applicable to locomotive engines, which is considered by a number of scientific men (as railway travelling is proceeding so rapidly) well calculated to supply a desideratum, and which is likely to prove a great national benefit, by reducing the expence, and increasing the safety, of internal intercourse :-The advantages of it areFirst, the condensing the steam after it escapes from the cylinders, and the water produced thereby returned to the boiler to be wrought over again and again; by which means the boiler is rendered more durable, being kept perfectly free of incrustation or deposit of any kind; and no stoppage is required to take in water; of course freeing the engine of the burden of carrying a supply along with it.-Second, The air that supports the combustion of the fuel is considerably heated previous to entering the ashpit; by which the smoke is completely consumed, although fresh coal be used in the furnace. Consequently a great saving in the consumption of fuel is effected. It is pleasant to add, that an experiment has been made with the apparatus, which is exceedingly simple, and found to answer all the purposes intended, and for which a patent is in progress. The inventors are William and Andrew Symington, whose ingenious talents are likely to be of as great benefit to their country as those of their father, the late William Symington, celebrated as the author and introducer of practical steam navi. gation.-Edinburga Chron.cie. LONDON: Printed and Published for the Proprietor, by W. A. Robertson, at the Mechanics' Maanzine Office, No. 166, Fleet-street.-Sold by A. & W. Galignani, Rue Vivienne, Paris. PROSSER'S PATENT CHUNK STOVE. The approaching recurrence of the winter season (of which whilst we write we are sharply reminded by a shower of sleet) has brought with it the announcement of a multitude of devices for the alleviation of its attendant discomforts. The last year's frosty atmosphere was warmed with a goodly supply of carbonic acid from Joyce's charcoal burner; the year before was characterized by the Arnott mania; but the present winter will be prominent in the annals of warming and ventilating, not for any particular plan, (unless it be that of the subject of the present article,) but for the great number of stove doctors that have obtained diplomas to practice, by paying the fees of the patent offices. The cheapness of fuel in England has, until of late years, kept out of the action of the probe of the professed inventor the primitive and un-scientific methods usually adopted in making the heat obtained from combustion useful in difusing domestic, official, and personal warmth whilst on the continent, where the material is dear, the closest attention and most refined ingenuity have been exercised in the matter. The Parisian porter, who warms his " cierge," and cooks his meals, with a handful of charcoal a day-or the Dutch vrow, who boils her kettle with a few ounces of carbonized turf, would look with amazement at the quantity of bright blazing coal burnt by an English person in the same station of life, and for the same purpose. But a revolution con. is now in progress in this matter. In one provincial paper, (the Midland Coun ties Herald) which we have just taken up, we observe advertised no less than six new stoves, viz.-" the Olmsted Patent Air Stove," "Chesterman's Patent Self-regulating Water Stove," "Smith and Co.'s Patent Arnott Cooking Stove," "the Leamington Patent Air Stove," "the Patent Healthy Urn Stove," and the subject of the present article, the Chunk Stove." This new candidate for public favour— but to which no favour is likely to be shown unless it merit it,-is the invention of Mr. Richard Prosser, Civil Engineer, of Birmingham, a gentleman well known in the mechanical world for his talent and ingenuity. It is extremely simple, correct in its principle of action, light, neat, and easily set or removed; as to its other advantages we must allow its proprietors to speak for themselves. Before proceeding to unfold" the advantages" of the invention, we must observe, that a rather mal-à-propos quotation has been chosen to grace the prospectus. All who have read Dr. Kitchener know that he was a great lover of a good coal fire, and it was not without an oblique reference to the heating apparatus-doctors of his day that he apostrophised his readers :-" Ye, who from caprice or parsimony sit shivering and murmuring, and refuse to employ the coal merchant as a substitute for the sun, may soon spend in physic more than has been saved in fuel." The good doctor, of course, could not have referred, by anticipation, to Mr. Prosser's invention, and we should be most happy and gratified to find that the words Chunk Stove could be substituted for coal merchant in the above excerpt. "The advantages of the Chunk Patent Stove, are, its entire freedom from dust or smoke, its very great economy of fuel, and its perfect safety. This stove has no door or other aperture out of which smoke, dust, or effluvia can pass into the apartment-hence its promotion of health and cleanliness; after a fire is lighted, all that this stove requires by way of attention, is, to let it alone' for twenty-four hours--hence the economy of time resulting from its use. "When your apartments,' says a medical writer, are contiguous, keep them at the same temperature, and remember that colds are caught nine times out of ten in the house. We suddenly change Bengal for Siberia, by going from a warm room into a cold one, and attribute our rheumatisms, coughs, and consumptions, to our climate, instead of our folly.' 64 Those who are fond of the morning fragrance- dust and litter of cleaning grates, and the racket of shovels, tongs, pokers, fenders, and coal-hods during the day, must forego these pleasures in the use of the Chunk Stove, which is chiefly recommended to persons of a more quiet turn of mind, who, during winter, or a 'severe English spring,' may wish for the climate of Naples with PROSSER'S PATENT CHUNK STOVE. out the trouble of a voyage. Wherever warmth is required, this stove is applicable; and its use, in all cases, prevents drafts of cold air into the apartment, and that dryness of the atmosphere which is so injurious to health. It may be used to warm entrance halls, dressing-rooms, laundries, nurseries, drawing and diningrooms, greenhouses, schools, countinghouses, store-rooms, offices, ships' cabins, workshops, houses of industry and correction, lunatic asylums, cabinet, musical instrument makers and joiners' work-rooms, printing offices, dryingrooms for paper, linen, gunpowder, drugs and chemicals, japanning and lackeringrooms, for airing unoccupied rooms or recently erected buildings, and for the important purpose of housing grain in wet harvests, and drying bricks, tiles, and pottery. The fire touches no part of the outer case of the stove, it cannot, therefore, become over-heated so as to burn or vitiate the air of the apartment; it may be placed in any part of the room, and the smoke conveyed in a two-inch leaden pipe, a convincing proof of its safety." The following description of the invention is an abridgment of Mr. Prosser's specification: "My apparatus for heating apartments, consists in a peculiarly constructed stove, which I denominate, for the sake of distinction, The Chunk Patent Stove.' It is formed of three essential parts, namely, a base or stand, a portable furnace or fire pot, and an envelope or case. The base is a circular plate of cast iron, standing on three feet, with three concentric rings on its upper surface, having an aperture in its centre, and a valve adjusted to such aperture, to regulate the admission of the external or atmospheric air, and a tube or flue for the escape of the gases of combustion, in the manner hereafter described. The portable furnace consists of a conical bucket of sheet iron (with or without a lid or cover) having an iron grate inside, supported at about one-sixth part of the depth of the bucket by three studs or brackets, projecting about half an inch on the inside, which prevent the grate from being displaced by the weight of the fuel, and forming underneath the grate an ash pit or receptacle for the ashes or dust caused by the combustion of the fuel employed. In the centre of the ash 147 pit is placed a funnel or chimney, covered at the top to prevent the ashes falling through and perforated on all its sides to admit the external air. From the centre of the lid of the bucket a short tube projects, covered with a valve which closes by its own weight, when the envelope is removed from the base, and when the stove is in use, a lever opens the valve by pressure against the envelope. The envelope, or case, is a cylinder of sheet iron closely covered at the top, and adjusted at the bottom to the upper surface of the base of the stove. When it is desired to use the stove it is requisite that the tube for the escape of the gases of combustion should be let into achimney, common air flue, or be connected with the atmosphere in any other suitable manner, so as to cause a draught of air through the stove; a sufficient quantity of sand is then to be strewed between the rings on the upper surface of the base of the stove to prevent the escape of smoke or vapour; fuel is then to be put into the fire basket or furnace, which is to be placed over the aperture in the base; and the envelope is lastly to be adjusted over the furnace and on the base of my stove. It will be obvious from this statement, that when the stove is thus in use, the external air for maintaining combustion is admitted through the aperture A in the base of the stove and up the funnel at the bottom of the furnace into the ash pit, formed between the grate which supports the fuel and the bottom of the fire bucket; the air then passes through the fuel, and the gases evolved during combustion are carried upwards through the tube in the lid of the fire bucket, and thence downwards between the outside of the furnace and the inside of the envelope into the flue F, communicating with the external air. Or in case of there being no flue, the gases may be exhausted by mechanical means and delivered into the atmosphere at any suitable place. The stove is shown, as in use by the sectional elevation (see front page), and it will be perceived, that the valve G in the lid of the furnace is kept open (as it must be to allow of combustion going on) by the lever pressing against the inside of the envelope. The ring in the centre of the base of the stove is for the purpose of preventing the sand falling through the aperture A; the next ring B, is to receive the fire-bucket, |