The microscopist often desires to secure in permanent form, the beautiful and curious objects which are revealed to his eye. Recourse is frequently had to the pencil and the prism, success being in direct proportion to the skill. Photography affords the best means, and by its employment we obtain exact copies of the magnified objects. Such pictures are called micrographs, and are produced by combining a microscope with a photographic camera. These combinations are generally expensive ; but their operation is simple, and they are easily managed. Mr. Louis Edward Levy, of Milwaukee, Wis., sends us some micrographs of his own production, which are creditable to him as an amateur, especially when we consider the simplicity and cheapness of the apparatus by which they were produced. Over the eye-glass tube of an ordinary achromatic microscope, he places a sleeve or ferule, to which is attached a small box, having its rear part open so as to receive the plate-holder which fits nicely into the box. The interiors of box and plate-holder are painted black. In focusing, a frame with ground glass takes the place of the plate-holder. With a microscope and camera, thus made, all objects visible by means of the microscope may be readily photographed. Mr. Levy states that his box was made of tin, and the whole expense was only $3. Keport on Steam Boilers Exhihited at the Recent Fair ot the American Institute. THE HARRISON SAFETY BOILER—FIRST MEDAL AND DIPLOMA.—1st. Safety. 2d. Economy of space. 3d. Economy of fuel.—This boiler was the only one which was found reliable and capable of driving the engines at the Exhibition, and which did furnish all the steam for the competition tests of the engines. Root's Wrought-Iron Sectional Boiler—Second premium and diploma for facility of repairs and economy of space. If any of our readers have been kept awake by the problem we gave them last week in regard to this report, they may now rest easy—the report is made. How about the evaporation power of these boilers ? How about the quality of steam produced? How about the boilers exhibited, not mentioned in the report ? We recommend any who wishes to see how much can be said without saying anything, to put the report on engines and this on boilers side by side, and study them together. The Gold Hill Fire StIJI Burning. The terrible and fatal fire which broke out in the Gold Hill (California) mines on the 7th of April last, and which resulted in the destruction of a large number of lives, is still smouldering. After it had been reduced to close quarters, it was carefully walled in, and work was again started in different directions around it. It was thought to havei been extinguished long ago; but such, it appears, is not the case, for a few days since some miners work'ng between the 600 and 700-foot levels of the Kentuck mine suddenly picked through into a space where there was plenty of fire, finding large brands of it. The place was at once closed up again. Being as far as possible shut in and kept from the encouragement of atmospheric air, the fire merely smoulders, but it is there, nevertheless, and may keep on burning for many months to come. It can do no particular harm, however, as it is merely burning out the old timbering where the mine has been worked out. Mtuary—-Death of HIr. .Tohii Degnon. We regret to announce the death of Mr. John Degnon, whom our readers will recollect as the engineer who took the locomotive Best Friend to Charleston in 1836, and set it running, and therefore claimed to be the first man who ever ran a locomotive in the United States. When we saw him last he appeared in good health, but he died of paralysis, at Boston, on the third of December, aged 59 years. He was a skillful mechanic. He learned his trade at West Point Foun-dery, and has been successively engineer on the steamships Arctic and Be d'Italia. REMITTANCES should be made in money orders, bank checks, or drafts, if possible. When neither of these can be procured, send the money in a registered letter. The present registration system is virtually an absolute protection against losses by mail, and all postmasters are obliged to register letters whenever requested to do so. AGENTS who receive their weekly supply of the SCIENTIFIC AMERICAN through news companies, are urged to canvass their localities. By a little effort among intelligent mechanics and manufacturers, they can add largely to their lists. We will send specimen numbers, when desired, for that purpose. SUBSCRIBERS who wish to have their volumes bound, can send them to this office. The charge for binding is $1'50 per volume. The amount should be remitted in advance, and the volumes will be sent as soon as they are bound. CITY SUBSCRIBERS will continue to be served, either at their residences or places of business, at $3'50 a year. Send in your names and the carrier will serve you faithfully. OUR rule of prepayment of all subscriptions is so rigidly enforced that whoever receives the paper regularly may consider it paid for. No names are entered ots\ t/tje subscription bjooks Without advance payment, Powerful Turbines. A correspondent of the American Odd-Fellow, which, by the way, is a very well conducted and popular magazine, thus describes the turbines used in the Mastodon Mill, in the village of Cohoes, New York. The entire number of looms in this mill is fourteen hundred and eighty-six; five hundred of which are located on the first floor." These looms and the other machinery of the mill are driven by three " immense turbine water wheels, made by the Ames Manufacturing Company, which operate the main shaft, and possess an aggregate driving capacity of over eleven hundred horse power. This pit having an extreme depth of forty feet, with a floor twenty-five feet from the surface, which hides the water wheels from a top-view, is in reality an underground two-story building. Three mammoth cast-iron cylinders, eight feet each in diameter, convey the water from the canal on the west side of the building to the wheels ; the volume of water being regulated by a sort of tiller located in the pit, and connected with the flood-gates. The perpendicular shaft of each turbine is connected with the main shaft by beveled gear, and the united power exerted, if so applied, would reverse the motion of the great Burden water wheel at Troy, and drive the machinery of a good- ; sized manufactory besides. The shaft to which this wondrous ' power is applied is supported by three granite abutments, and forms the axis of six ponderous driving pulleys, twelve I feet each in diameter. The immense belts which radiate to all parts of the building are in keeping with the massive pulleys and gearing. These are each two feet wide, and the longest one, reaching to the fifth story, measures nearly two hundred feet. At the north end of the pit, two rotary force pumps are located, which, in case of fire, can be instantly geared to the main shaft by means of a sliding cog wheel, and are jointly capable of throwing six thousand gallons of water per hour." A Balloon View of a ILoiicloii JFog. A London paper says :—" On Wednesday afternoon, when London and the suburbs were enveloped in a dense fog, Mr. Coxwell mafe a balloon ascent from the Hornsey Gas Works. [ The ascent took place at 2:40,when the atmosphere was clear. Boon after three o'clock the fog extended exactly in the direction the balloon was traveling, and presented a strongly defined line of vapor stretching for miles in an easterly direction. The formation of this fog, as witnessed by Mr. Cox- : well from his balloon car, was, we hear, one of the most in- j teresting occurrences in the adventurous life of the experienced aeronaut, and will no doubt be fully described. Over the Forest, near Woodford, Mr. Coxwell and his companion were unable to see the earth at a hight of only fifty feet, and it was only by the aid of a rope trailing on the ground, that a level course could be regulated so as to select an open spot i on which to alight. While holding conversation with some men who were following the balloon, and could only hear the rustling of a rope among the bushes and trees, the aeronauts were supposed to be poachers. Keepers, who were in close pursuit, rushed upon the strangers when Mr. Coxwell cast his grapnel in a hedge, and great was their surprise when they discovered what kind of a net and cordage it was trailing over the park. So dense was the fog, that the balloon j could not be seen, and the voyagers were supposed to be running along the ground, although Mr. Coxwell proclaimed his balloon, but this was thought to be a ruse to draw off the keeper's attention. Notwithstanding the difficult position, Mr. Coxwell was placed in as to landing, still a safe deseent was made." A PEANUT picker was among the new labor-saving machines exhibited at the Virginia State Fair Hitherto the nuts have been picked off the vines by hand ; four bushels a day being the fair average for a hand. A farmer who raised 1,000 bushels required ten hands for nearly two months to save his crop, at a cost of fifteen cents per bushel. The crop raised on the south side of James river, between Petersburg and Norfolk, is estimated at 1,000,000 bushels a year. To save this crop would require the labor of 6,000 hands for two months, at a cost of $200,000. The new machine is said to save much time and labor. A RAZOR INDEED !—Mr. J. W. Churchill, of Willkesbarre, Pa,, thinks people hone and strop razors too much. He has used one for two years without either honing or stropping it, and it still cuts his beard well, though latterly it begins to pull—a little. He means to use the razor until compelled to sharpen it, but he can still cut a hair held in his fingers with it. Mr. Churchill thinks Ms razor hard to beat, and we think his beard must be still harder to beat if it has with constant use not dulled a razor in two years. The very I thought of it makes our face smart. CLOTHES WRINGERS.—These indispensable household articles are becoming more generally introduced than almost any other labor-saving machinery. It is but a few years since the first patent was taken out on a clothes wringer and now there are but few families that do not use them. A good article in the clothes-wringer line is advertised on another page. WATER WHEEL EXPERIMENTS.—We have the promise of a report of the recent trial of water wheels at Lowell, Mass., for publication in our next number.