QUESTION PROPOSED FOR DISCUSSION

AT THE INSTITUTION OF CIVIL
ENGINEERS.

Is there any substance of less speeific gravity than brick, that is equally incombustible, and as applicable for use in fire-proof floors?

MINOR CORRESPONDENCE. Thermometric Phenomenon.-Sir, On Sunday, Jan. 10, I observed a phenomenon so rare, as to deserve recording. At mid-day, Fahrenheit's thermometer indicated 360, with a sharp north wind and a clear sky. Now, though the thermometer was 40 below the freezing point, there prevailed a hard black frost; the ice in the puddles was perfectly black, and the road as hard as stone: in short, it was freezing fast at the time. -I have every reason to rely on the correctness of the thermometer, which had a north aspect sheltered from the wind. No doubt, the frost was occasioned by the rapid current of air which swept along the road, and from which current the thermometer was free. Every body knows how much colder a wind is to the feel than a calm, though the thermometer may indicate the same temperature in both cases; but I never yet saw an exemplification of it similar to the one mentioned here-it may be equally new to inany of your readers, whose amusement is the object of,

Yours, &c. J. B. Jun.

Camberwell, Jan. 24, 1830.

Jones' Cylindrical Iron Wheels-The use of these wheels appears to be now becoming very general in the metropolis, particularly among brewers, distillers, coal merchants, &c. A correspondent, at Hull, requests we will suggest to the patentees the propriety of taking some steps to introduce them throughout the country" the expense of carriage, and the difficulty which may attend the repairing of them at a distance from town, preventing country persons, like himself, from availing themselves of this admirable invention."

Jackson's Patent Studs.-(From R. W. 30, K. S.)" Mr. Editor, As much has been said concerning Jackson's Patent Studs, in your interesting work, allow me, through the same medium, to apprise your numerous readers, that these Studs are not sold; but if you wish to avail yourself of the benefit of the invention, you must send your boots and shoes to the patentee to have the Studs put in. The cost, I understand, is 1s. 6d. (by no means an exorbitant charge): but would not the patentee reap more benefit from his invention by selling the Studs alone to such as are or may be inclined to purchase them? I live at some distance from the metropolis, and would avail myself of the proprietor's ingenuity, but for the expense of carriage to and from London, together with the expense of studding, which would, at the lowest calculation, be 4s. 6d. per pair. Since I first entertained the idea of writing to you, I have learnt that no patent has been taken out for the invention, and that a Tradesman in our neighbourhood will make some slight improvement in them, and establish an agent in London, as also all the large towns in England, for the sale of the Studs."

[Our Correspondent has been misinformed'; there is an existing patent for the Studs in queston, which it will be dangerous, we apprehend, to infringe.-EDIT.]

MISCELLANEOUS

Men-of-War's Boats.-A new mode of constructing boats for ships of war has been invented by Mr. Johns, of Plymouth dock-yard. There are no timbers used, all the planks coming up from the keel to the gunwale, diagonally, not very stout, but rendered strong by being again crossed by others, diagonally placed, but in the opposite direction. The boat so constructed is stronger than the ordinary one now in use; the seams never open in straining, which prevents leakage; and another great advantage is that she is only half the weight of one on the old construction of the same size. The planks are all fastened together by copper nails, thickly set. There has been a boat of this construction on trial attached to the Britannia, 120, and although in constant use for eighteen months, it has not required any other repair than the gunwale streak."-United Service Journal.

Sparkles in the Sea.-The phosphorescent-like lights observed in the Mexican Sea, shine with greater brilliancy (in April) than any other part of the ocean; and this, I can assert without mistake, as I bestowed great attention on the subject, and had the acquiescence of others. Some of these lights were very large, and flashed like the priming of a cannon, sometimes at a long distance from the vessel. I observed that the little shining sparkles were here confined to the sides of the vessel and her wake, and that the waves when they broke into foam did not sparkle, which is quite different from what we had noticed before in the passage out, and in the Carribean Sea. Contrary to Dr. Franklin's assertion, the sparkles are seen in the water of the Florida stream as in other parts of the ocean.-Correspondent of the United Service Journal. The statement of Dr. Franklin, to which this contradiction is offered, was in these words :-" Having crossed this stream (Florida) several times, in passing between America and Europe, I have been attentive to sundry circumstances relating to it, by which to know when one is in it; and besides the gulf-weed with which it is interspersed, I find that it is always warmer than the sea on each side of it, and that it does not sparkle in the night."

The Pantouranion.-A valuable astronomical instrument, invented by Mr. W. Shires, the mathematical tutor, in January, 1829, has been since improved by the same author, and rendered capable of finding its own meridian, the right ascension, declinations, longitudes, and latitudes of any celestial object; the day of the month and hour; the hourly, daily, and annual variations; the state of refraction, moon's parallax, and precession of the equinoxes. It will also direct the observer in finding any planet, &c. mentioned in the "Nautical Ephemeris;" will point out the fixed stars, foretell eclipses, and, in a word, will form of itself a complete observatory. The instrument is an improvement on the equatorial of Mr. Shires; the principle of which, as first conceived, was explained to the Western Literary Institution, and in the "Mechanics' Magazine," No. 297, for April, 1829.

INTERIM NOTICES. Januarius-Certainly not.

Communications received from J. G.-S. Y. -Mr. Baddeley-T.-Mr. Jopling-A. B.-. Mr. Gray-Mr. Thorold-R. L. D.

LONDON: Published for the Proprietor, by M. SALMON, at the Mechanics' Magazine Office, No. 115, Fleet Street; where Commu nications for the Editor (post paid) are requested to be addressed.

M. SALMON, Printer, Fleet-street.

Sir,-The "Improved Bee-House," published in the "Mechanics' Magazine" of July 4, 1829, is, I think, a very pretty toy: but as I am induced to believe that it is essentially necessary for the entrance into the hive to be stationary, and that the bees, if possible, should have the sun to shine upon them from morning till evening, I do not very well see how it can answer the purpose intended.

But if, in some respects, I undervalue Mr. Saul's beautiful box, I really feel much obliged to him for having given me the idea of so hanging my hives, as that without the least inconvenience, and at no additional expense, they may be weighed by any child of ten years old, the motion not being perceivable by the bees.

Among the many discoveries and improvements that are daily taking place in this gallop of intellect, perhaps nothing is more deserving of praise from the labouring-classes of society for the services rendered them, than is the new method of managing bees by Mr. Thomas Nutt, of Moulton Chapel, Spalding, Lincolnshire.

Above £300,000 a year is said to be paid out of England for the importation of foreign wax and honey. Till now, bees have had attention bestowed upon them, as ants have had, and little more, i. e. by a few persons curious in natural history: but the management of them has never yet been taken up as a consideration of general interest and profit-I had almost said as of national importance.

Are they to remain for ever, or any longer neglected, standing upon the damp, dirty, rotten bench of the labouring man, now that it has been satisfactorily proved to us, that by this new mode of looking after them, they have already in one instance produced-and that in a most unfavourable year-four hundred pounds weight of honey from one swarm: six swarms producing, in the same year, 1192lbs.; and of so superior a quality, that four times the usual price was paid for what was offered for sale? Are we still to introduce foreign wax and honey, when at home we can supply the quantity required, and of a qua

lity by no means inferior to any we import? Is charity so dead in the country, that merely from want of being better informed, the poor, hardworking man shall still continue to struggle on, when so easily his lot may be improved? I trust not. But through the medium of your invaluable Magazine, I hope, Sir, so to recommend this new plan to the notice of the public, that it may be universally inquired after, and be adopted in every village throughout the united empire.

If there be any merit in the principle of the double-cottage hive, of which I now send you a sketch, it is due to Mr. Nutt. The method of managing them I leave for him to explain, as I think it would be an injustice to rob him of the benefit that, I trust, he will derive from the discoveries he has made.

His plan, however, I think I have greatly simplified. By removing the benches, I have ensured the cleanliness of the hives; that they shall be kept dry; and that all insects shall be kept from them. And by placing the steelyard under them, as they hang either suspended from a rope, or branch of a tree, from the beam of an outhouse, or are supported by props, it can be certified what progress they make, if necessary, ten times a day, in as many minutes. The expense of the rope is trifling; and even that might be almost altogether done away with, as a few nut-sticks, wattled together, would serve the purpose equally well. If this hive did not hang under a shed--which is recommended -a piece of painted canvas, earthen pan, or thatch, might be placed over the top of the box to throw off the rain, &c.

an

It will be objected against me, that if we collect such enormous quantities of honey, the price will so fall, that it will not be worth a farthing a pound. To this objection I answer, that I am much mistaken if, by leaving a proper supply of honey for the bees during the winter, they may not be made to furnish wax to a very considerable amount; for which there will be always a demand that will ensure its being a good marketable commodity. A spirit also of a very superior quality

may be made from honey. Again, as in the hive itself, do we not see in every class of society the drones as well as the workers? Are there not many persons that no spur to industry will make industrious? No; there is no fear of there being too much honey, and still less of there being too much wax. When the price will no longer but remunerate the poorest of the people for their toil, the business will fall into the hands of those only who are content to gain the merest trifle: but, at least, let us encourage this branch of industry amongst our own poor, till we have driven entirely from our markets all foreign supplies-for, were we only to benefit the labourer, or mechanic, by showing him how he may add a trifle more per annum to his wages, it would be no small advantage; but we should, moreover, in a very considerable degree, improve their general habits, by introducing so moral a lesson to their attention; and the interest they would take in ornamenting their little gardens, would greatly add to the beauty

of the country. Every grain of mignonette-seed sown in the garden is an additional support to the hive of the labouring man.

The hives that I recommend may be placed, like a bird-cage, at a window, only by hanging them on the steelyard from the beam, instead of raising them by the steelyard when weighed. And if brought close to the window, the bees can go out and come in without the least inconvenience; they may be looked after by the cottager's wife, or the mechanic, without leaving the house, or by any infirm person unable to leave the room. I have known twenty hives to be kept by a shoemaker in a small backcourt, not twelve feet square, at the back of his house, and in a town: they may even be kept in a garret, in the middle of a large town.

Persons of no mean name or rank, from the desire of doing good to their labouring poor, have already honoured Nutt with their patronage; such as their Royal Highnesses the Duke and Duchess of Gloucester, the venerable