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MR. FINE'S THEORY OF ELECTRO-VEGETATION,

niently spared from your valuable pages. I would just remark, that this part carries with it a strong air of probability, and would particularly recommend it to the perpetual-motion" hunters, those mo, dern alchymists, if any of that wayward tribe still remain. Let them leave their sublime projects in abeyance for a little while, and set about answering the following proposition; before this task is finished, they will probably have discovered that seeking after a perpetual motion is something like a man with a wooden leg running after a hare-the farther he runs the farther he gets behind. The proposition to which I allude is in the following words:* "If there could exist a power having the property of giving continual impulse to a fluid in one Constant direction without being exhausted by its own action, it would differ essentially from all the other known powers in nature; all the powers and sources of motion-with the operation of which we are acquainted when producing their peculiar effects, are expended in the same proportion as those effects are produced." This is certainly a very strong and comprehensive proposition, and furnishes a rule which is, I believe, of universal application. It would thus appear, that this superlative class of mechanical geniuses propose to accomplish more than has been attempted—no doubt for wise purposes-even by the Ruler of the universe himself. I must here close these rather desultory remarks for the present, but shall recur to the subject shortly, as it appears to me to be of cousiderable importauce, and well worthy of investigation.

1 remain, Sir, yours, &c.

URSA MAJOR,

MR. MACKINTOSH'S ELECTRICAL THEORY
OF THE UNIVERSE, AND MR. PINE'S
THEORY OF ELECTRO-VEGETATION.

Sir, Having paid attention for some years past to electrical phenomena generally, I have read with considerable interest an electrical theory of the universe published lately in the Mechanics' Magazine, and also the very useful practical observations upon electro-vegetation, by

• See Mechanics' Magazine, No. 665, p. 233.ED. M.M.

your correspondent, Mr. Pine. I have made some calculations with respect to the electrical theory, which I am afraid are far from being correct, and, perhaps, hardly worthy of a place in your periodical; however, they may be the means of eliciting something better from some of your able correspondents.

Taking 365d. 6h. to have been the true length of the tropical year at the commencement of the Julian period, and comparing it with what is considered to be the correct length at the present day, viz. 365d. 5h. 48m, 52s., we find about 12 minutes due to the earth's secular acceleration in the last 2,000 years. The year contains 525 948 minutes, which heing divided by 12 (the quantity due to the secular acceleration), and multiplied by 2,000, gives 87,658,000 annual revolutions of the earth before she falls back into the sun. In the same way, taking 4m. as the quantity due to the moon's secular acceleration; from her mean time as estimated by the observations of eclipses taken at Babylon about 650 years before Christ, and compared with her mean time at the present day, being a period of about 2,500 years, we find that the moon and earth will meet in about 2,700,000 years, and that this event will happen before the earth has advanced more than 3,000,000 miles nearer to the sun. These calculations are founded upon the supposition of the se cular acceleration being a constant quan, tity; but as the velocities of the planets increase as their distances from the sun diminish, the results here given must be very erroneous.

I was fearful, Mr. Editor, upon first reading this theory, that all our fine new railways would shortly be buried in the lunar ruins, and that some of the postdiluvian inhabitants of this earth, if any were so fortunate as to escape, might perchance dig them up and speculate with wonder upon the probable purposes for which they were designed, as we of the present day do with respect to the pyramids of Egypt.- However, it appears. there is no immediate danger.

I have also a hint or two to communicate relative to electro-vegetation, and should feel obliged if your able correspondent, Mr. Pine, would give his opinion upon them in his next letter. I have observed, that the common scarletrunner or French bean always twists in

STEAM CONVEYANCE BETWEEN PADDINGTON AND THE CITY.

one direction round the stick that supports it; I have often tried to make them turn the opposite way, but never could succeed. It appears to me that this is an effect of electricity, Indeed I am of opinion, that the whole of the clinging tribe of plants are indebted solely to this agent for the support which they derive from the more solid bodies to which they cling. It appears to me, that the delicate tendrils of these plants, when in an active state of vegetation and full of sap, are in a positive state, and are therefore attracted and upheld by the dry bark or other body in their vicinity, which may be in a negative state as compared with the highly active tendrils.

It has been noticed, that it is dangerous to stand under a tree during a thunder-storm; and also, that there is more danger under an ash than there is under those of any other species. It has also been noticed, that no sort of vegetable, but more particularly turnips, will thrive under an ash, even when the tree is entirely isolated and standing in the middle of a large open field. The farmers say, that the droppings from the ash-leaves when it rains poison the soil; but I suspect the true cause to be, that the high and spreading branches having a very strong affinity for electrical matter, absorb so large a quantity, that the turnips are deprived of the portion necessary to their proper vegetation. A friend and neighbour of mine, who has paid much attention to this subject, carries his notions considerably farther than I have presumed to go. He gives it as his opinion, that when a field is dressed or manured with lime, although the soil may be enriched to a certain extent, that the augmentation and acceleration of growth which is derived from the soil itself is comparatively trifling, but that a larger quantity of the vegetable nutriment is drawn from the atmosphere, which he attributes, in a great measure, to the chemical and electrical affinities which are called into action by the presence of the lime. In support of his opinion, he says: If I were to dress a field with lime, and plant potatoes upon it, I should not expect to have a heavy crop, and for this reason, we know that a heavy crop of potatoes impoverishes the land very much, from which it would appear, that they draw their nourishment principally from the soil;

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and as lime is of very little service to this crop, I conclude, that the land is not much enriched by its use. But if I sow barley in this field, I have the chemical action of the lime, aided by the bearded ears of the barley, forming so many thousands of conducting rods, drawing abundant nutriment from the atmosphere, which continually flows over them, charged with particles suited to their nourishment and growth."

With whatever respect these few observations may meet from your readers, I think, Mr. Editor, the subject of electrovegetation is one of great importance, and lies at the very root of agricultural science. If such of the readers of the Mechanics' Magazine, as may have the means of observing, would forward their remarks, that those which appeared valuable might be published, we would thus, by each casting his mite of knowledge into the public treasury, very soon be in possession of a practical informa tion, and be thereby enabled to extend our dominion over the physical world in all that relates to the means of subsistence, which must be admitted by all to be an object of the highest utility. Yours obediently,

Nottingham, April, 1836.

W.B.

STEAM CONVEYANCE BETWEEN PADDING-
TON AND THE CITY FOR HIRE.

Mr. W. Hancock, whose perseverance certainly deserves success, commenced running his steam carriages, the "Enterprise" and "Erin," on Wednesday morning last, at nine o'clock, from the station in the City-road to London Wall; from thence he proceeded to Paddington, and returned to the City. On the first day he performed three of these journeys, on the second, four, and on the third (yesterday), two, before noon. The average time of travelling over the above ground has been 1 hour and 10 minutes, including stoppages to take in passengers, water, and coke. This is just half the time the horse-omnibuses take in going over the same ground. In the 9 journeys performed, the number of passengers carried was 220, averaging about 12 persons each single trip. Mr. Hancock in. tends to run his carriages regularly the same number of journeys daily, for the present, and very shortly to increase the number.

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NOTES AND NOTICES.

NOTES AND NOTICES.

Currents in Water.-In the last number of Silliman's Journal, in an article on "currents in water," it is asserted, that if a tub or other vessel is filled with water, and a hole made near the middle of the bottom of it to discharge it, the water will acquire a rotatory motion from west to south, or opposed to the apparent motion of the sun; and if means are used to produce an opposite motion, upon withdrawing those means the former direction will be resumed. This cannot be the effect of chance, but of natural laws constantly operating.-Guernsey Star.

Household Manufacture of Sugar.- A remarkable proof of the facility with which beet-root sugar manufactories may be established is presented at this moment at Wallers, in the department du Nord. Four of the villagers, by advancing 50 francs each, have formed a joint capital of 200 francs, and with this they produced between 40 and 50 lbs. of sugar, of rather inferior quality, a-day. They employ curry-combs to rasp the beet-roots, which they put into a napkin-press to extract the juice, and then boil the syrup in common culinary boilers.-Ibid.

New Ships' Signal Lantern.-A most admirable invention has recently been brought into use, and is likely to meet with general adoption, intended to prevent those accidents which are the cause of so much loss of property, as well as the annual sacrifice of a number of valuable lives. It consists of a ship's lantern, of copper, strongly and efficiently constructed, and possessing the means of being regulated so as to show a light of different colour, according to the tack upon which the vessel bearing it may be sailing, or the position in which she lies. A set of instructions accompanies each lantern, by which the master is informed what light he is to show on each change of tack and position, and thus a mutual understanding is attained amongst navi gators as to the meaning of the signals exhibited. The changes of colours are effected by the following simple contrivance :-The lantern contains an interior case, capable of being turned round, and having windows of glass of several colours. The lamp of the lantern. has a strong reflector and powerful" bull's eye," or magnifier, to project the light, opposite which, in the outer case, is an aperture. By turning round the interior case, each coloured glass window is brought in front of the bull's eye, and thus a light of the colour required is projected.-Hull Packet.

Kemp's Submarine Apparatus.-We understand another attempt is about to be made to raise the hull of the Cameleon. by Mr. Kemp, who, having obtained a patent for the invention of his buoying principle, has received permission from Government to make an experiment on this ill-fated vessel, and in the event of its proving successful, the wreck as it may be raised will become the reward of the enterprise. Mr. Kemp's apparatus consists of a number of empty puncheons, each open at one end, and having a bar of iron across, by which, after being sunk, they are attached to a chain, previously passed round the wreck by the divers, who next employ themselves successively applying to each cask the elastic tube through which they are filled by the air-pump, and the water consequently expelled. The puncheons thus charged with air acquire a perpendicular position, and are so buoyant as to render certain the raising of any weight proportionate to the number of them employed. The operation of filling the puncheons with air will be comparatively easy in this instance, as from the favourable circumstance of the wreck lying in less than thirteen fathoms of water, little more than two atmospheres will be required, and scarcely any doubts are entertained of the attempt proving successful.-Dover Telegraph.

Massie and Ranwell's Puddle-Wheels.-A few days ago, the first public trial of this new paddlewheel for steam-vessels was made on the River. It was affixed to the Red Rover steamer, belong ing to the Herne Bay Company, which conveyed the female emigrants and agricultural families to the ship at Gravesend in which they embarked for Van Dieman's Land. After the emigrants had left the steam-vessel, to the starboard side of which the new wheel was affixed, the larboard si le being fur→ nished with the common wheel, the Enigration Committee, visiters, and several naval officers, proceeded to inspect the new paddle-wheel, a model of which was submitted and familiarly explained by Mr. Massie and Mr. Ranwell. The principle seems to consist in the exposure of the entire surface of the float to the water while in the most advantageous position for propelling, which upon approaching the surface becomes divided into a series of angular bars, which suffer the water to pass through the interstices, and thus transfer the action of the steam-power to the next floats in succession, instead of uselessly wasting it on the water-lift. A considerable ferment in the water (though the swell was not so heavy) was apparent, which, however, a littl alteration in the construction will considerably diminish, and which the experiment will enable the inventors to accomplish.-Weekly Dispatch.

Coins in the Clouds!-A Brighton physician lately adopted the following singular means of preserv ing some of the coins of the realm. He enclosed several of the last impression in a ball of war, which he placed in a bailoon of In lia-rubber suff. ciently inflated with gas to raise it several thousand feet above the earth, where, Boating in space the memory of our nation and its monarch, may be recorded for hundreds of thousands of years. Within the ball of wax was also placed a slip of parchment with the following letters cut out:"Anglia Martis X., 1336."-Dispatch.

Mr. W. J. Curtis-Received aud intended for early insertion.

H. M. M. shall have a place soon-no charge.

Communications received from Mr. DeakinMr. Simms-Mr. Peacock-R.-W. B-Mr. Merritt-Mr. Millichap -Americanus Mr. Mackintosh-F. N. O.-K. K.—A Railway Traveller.

The Supplement to Vol. XXIV., containing Title, Contents, Index, &c., and embellished with a Portrait of Mr. Walter Hancock, C. E,, is now published, price 6d. Also the Volume complete in boards, price 98. 6d.

Patents taken out with economy and despatch; Specifications, Disclaimers, and Amendments, prepared or revised; Caveats entered; and generally every Branch of Patent Business promptly transacted. Drawings of Machinery also executed by skilful assistants, on the shortest notice.

LONDON: Published by J. CUNNINGHAM, at the Mechanics' Magazine Office, No. 6, Peterborough-court, between 135 and 136. Fleet-street. Agent for the American Edition. Mr. O. Rick, 12. Red Lion square Sold by G. W. M. RETNOLDS, Proprie or of the French, English, and Americ Library, 55, Rue Neave, Saint Angustin, Paris.

CUNNINGHAM and SALMON, Printers,
Fleet-street.

Mechanics' Magazine,

MUSEUM, REGISTER, JOURNAL, AND GAZETTE,

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98 REPORT OF EXPERIMENTS ON THE EXPLOSIONS OF STEAM-BOILERS.

REPORT OF EXPERIMENTS MADE BY THE
COMMITTEE OF THE FRANKLIN INSTI-
TUTE OF PENNSYLVANIA ON THE EX-
PLOSIONS OF STEAM-BOILERS, AT THE
REQUEST OF THE TREASURY DEPART-
MENT OF THE UNITED STATES.
(From the Journal of the Franklin Institute.)

(Continued from p. 92.)

II. To repeat the experiments of Klaproth relating to the conversion of water into steam, by highly heated metal, and to make others calculated to show whether, under any circumstances, intensely heated metal can produce, suddenly, great quantities of highly elastic steam.

The first part of this query relates to the repetition and extension of the experiments of Klaproth; the second has reference to them, but may be determined by direct experiment, independently of the methods required for obtaining an answer to the first part of the query. It has been supposed that because the metal of a boiler was heated above the temperature at which the metal would produce steam most rapidly, it was impossible to account for the production of quantities of highly elastic steam by such a cause. The Committee, determined to make the fact of the production of high steam by intensely heated metal the subject of a direct experiment, and under circumstances as nearly similar as possible to those which may occur in a boiler, of which some parts, as the sides or interior flues, may become unduly heated, when not in contact with water.

The experimental boiler being arranged as already described, a small quantity of water was placed in it and boiled away; the heat being still applied, the temperature of the bottom was gradually raised. At different temperatures of the bottom, water was thrown in by the forcing-pump, and the effect of a given quantity on the gauge noted. The temperature of the steam generated was ascertained by a thermometer passing horizontally through the back head g, fig. 1, and two-thirds of the diameter above the bottom of the boiler: a second horizontal thermometer as near to the bottom as the rim of the

boiler would permit, served to show whether the heat was rising or falling, and was noted for this purpose. Both the windows of the boiler had glass three-eighths of an inch thick in them, without the cross-bar covering. The water injected was at 70° Fahr. The course of the water injected could be distinctly marked after the bottom of the boiler had become heated to redness, and was examined through the glass window d, fig. 3. The force of the pump carried it to the fire end nearly; the boiler being slightly inclined to the back end, the water slid back in one or more dark masses, moving down the central line, or diverted up the sides, greatly agitated and frequently changing its shape. The water generally disappeared at the back end, though parts were retained by accidental spots of sediment, and disappeared upon them. The table below gives the results of the second day's experiments on this subject; they were terminated by violently bursting out the glass window at the fire end of the boiler.

The height of the lower thermometer, as noted by an observer at the back end of the boiler, is given in the first column of the table, with the appearance of the bottom of the boiler, both being examined before injecting water. The gauge was allowed to fall to the height denoting one atmosphere, before giving the number of strokes of the pump, from which the quantities of water in the third column are taken. The pressures in the fourth column were noted on the gauge by the same experimenter who threw in the water. The first effect was examined through the back window D, fig. 3, and the temperature of the steam produced, before the gauge began to fall, was noted as is recorded in the fifth column. As in all the experiments, the steam was rapidly produced, and the total effect was the object sought, the time was no further noticed than to ascertain that accidental circumstances, independent of the temperature, rendered the total time of evaporation very variable, and that the maximum of effect was always passed in the space of from one to four or five minutes.

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