A thermometer, plunged inte tht suow to the depth of four indios, will mark nine degrees more heat thaii at the surface. ín ordinary breathing a man's chest takes in at one breath about twenty cubic inches of air, the bulk of a fullsized orange. If the existing waters of the sea were increased but one-fourth it would drown the earth, with the exception oi sorne mountain summits. ïo estímate the distance of a storm observe how many .seconda elapse between the flash of lightning and the thunder and multiply them by 1142 the number of feet sound travels in i second. Br. Arnott allirms that no wave of th(! ocean rises more than ten feet from the ordinary sea level, whicli, with the ten feetits surface afterwards descends gives twenty feet tor the wholeheight A French surgeon mitigates pain by administrating a series of wave sounds to the affected part by means of a tunIng fork and a sounding board, ifeuralgia is cured speedily. The vibration is kept up by an electro-magnet. A new industry, the extensivo cultivation of ilowers for perfumery purposes, is about to be started in California. In Em-ope it is very remunerative; a good erop of lavender will yield $1,500 per acre. The best steam engine now existing (which consumes two pouïids of coal an hour a horse power) yields about one-tentli of the power which the combustión of the coal would theoretically produce, measured by thermal units. An automatic bulletin has been placed over the clock in the Boston office of the Fitchburg railroad, which exhibits the telegraphic reports of all the western and northern trains, tells when they aro d-ue and how late they are,. For a healthy adult man the average quantity of food required during twenty-four hours is, sixteen ounces of bread, three and one-half ounces of butter, and flfty-two fluid ounces of water. A French electrican has devised an ingenious electrical low-water signal for stemn boilers, which indicates the existing water level at any distance from the generator, and when the water lias sunk below a certain point rings a signal bell, while ;it the same time the sign "low water" appears oa tlie indicating tablet. A paper dome, thirty íeet in diameter and weighiiig aboufc two tons, is being ínadefor the new observatory at West Point. It will weigh only onetenth as much as a copper dome of equal size. , The manufacture of thread f rom wood, for sewing and crochet purposes, is found so far practicable tbat an establishment for the industry has been started near the town of Xorkoping, in the middle of Sweden. ïhe system pureued is to wind the tbread in balls, by machinery, either by hand or steam, wliicli with tlie labellingtakesone minute twelve seconds per ball. A tree which grows in Xevada anc' is known as mountain mahogany is as hard as wood, and is of very fine grain. It is of a rich red and very heavy. As fuel it produces intense heat, burning with a blaze as long as ordinary wood would last, and then taining its i'orm and lasting twice as long as ordinary wood. The only objection to it as B fuel is tliat it burns stoves out more rapidly than coal. Cast iron is used even in wrouglit iron boilei-s for grate bars, ash pans, furnace doorn, uptake doors, man-liole plates, liaud-hole plates, valvechambers. steain pipe, feed pipe, blow pijie and dry pipe. Ueing unyiekling it is not well adapted for apparatus Hable to sudden changes iïom expansión by changes of temperatura, lt can not be patched or menrted as wrought iron can. This ability to be inended is one oï the chief advantagesof wrouglit iron tor boiler work. Oolor-blindness as a cause of disasters is nów tolerably well recognized by those in or by water. Sounds, however, as well as colors, are employed as signáis, and the inability to distinguisli the former may prove as fatal as alack of sensibility to the latter. Sometimes, too, persons lu ving excellent eycs have very poor ears, and the contrury is also true. ]ut perhaps the gravest source of catastrophes, especially in railroad tntvel, is the tendency oi' engineers to what mar be called absence of Blind, especially when those men manage thoir locomotives for montlis and years over the same monotonous track. The practical suecess of the electric raihvay in Berlin luis doubtless stiraulated inventive talent the worhl over but a velocipede propellcd by eleetrici ty is the first vehicle to tall into line behind the Germán sheet car. An electricinn of Paris has succeeded ir driving an Knghsh tricycle ior an hour along the streets of Paria, by ineans o electricity stored in a "secoiidary battery" of Plante's make, and two small Deprez eleetric motors. The vehicle wi.tlj its occupantweighed 400 poundd, and it was driven at thespeedof anordinary cab; but, by improving the mechanism, the inventor hopes to raise the speed to twelve miles an hour; and the modification whieh lias since been effected on the Plante battery by M. Faure, will no doubt en.ible a supply of electricity to be stored up, capable of working the tricycle for many houi-s. The white saline substance that "comes put" upon brick walls, and which has been a souree of annoyance to a great eoiany, may. accórding to the American Architect, be remedied. In reply to a query on tlie subject, it says: The "saltpetring" of brickwork can generally be prevented by adding oil to the mortar, at tlie rato oi' a gallon to the cask of lime. If cement is used in the mortar, an additional gallon of oil must be allowed for each cask of cement. Linseedoil is generally employed, but any kind wliich does not contain salt will answer. Tlie incrustation, once formed, can be removed with hot water, or by the muriatic acid generally used for cleaning down brickwork, bilt it will reappear again by exudation 1 rom the interior of the wall, and usually lcaves a permanent black or brownstain. Some very elementary lessons in physics are evidently needed in Francorua, Pickens County, A hu A correspondent at that plaee, writing to au honored contemporary, gives tlie following reasons for liis lisbelief in the axial r6 vol ut Ion of the earth: "When two objects pass each other, going in opposite diiecüons, they pass very quiekly, as, tor instance, a bird ilying west ought to pass objects npon the earth much more rapidly tlian wlien it fües eiist. I!ut tliis is not the case. A bird passos no more rapidly going ivest tlian when it flies east; a ball thrown againsta house in á wcstorly direction does not rebound any more than when thrown east. Yon inay send a balloon upabove your head and let it stand 24 hours, and at the expirationjjf the 24 lioura the balloon will be direelly over your liead. I have studied the reasons giveii in astronoiuy and ünd nothing to refute my observations." Dr. Henry MacCormac, of Belfust, Ireland, writes tliat it is not at all neceasary or inevitable tluvt & person knowing nothing of the art of swimming should be drowned if he depends simply and entirely on the powers for self-preservation wlth which nature has endowed htm: The pith of the Doctor's remarks is contained in the following paragraph: "When one of the inferior animáis takes the water, falls, or is thrown in, it instantly begins to walk as it does when out of the water. But when a man who cannot "swim" falls into the water, he makes i few spasmodic struggles, throws up his anus, and drowns. The brute.on the other hand, treads water, remains on the surface, and is virtually insubmergeable. In order, then, to escape drowning it is only necessary to do as the brute does, and tliat is to tread or walk the water. The brute lias no advantage in regard of his relativo weight, in respect of the water, over man; and yet the man perishes while tke brute lives. Xevertheless, any man, any woman, any child, who can walk on the land niay also walk in the water justas readilyas the animal does, ana tnat without any prior instructions or drilling whatever. Throw a dog into the water, and he treads or walks the water instantly, and there is no imaginable reason why a human being under like circumstancee sliould not do as the dog does. The brute, indeed, walks in the w.iter instinctively.whereas man has to be told." Discussing the question of heat in mines, the Virginia City EnUrprise gives the following very interesting points upon this important subject: "Limo is undoubtedly one cause of heat in our mines, but it is not the only nor the great heat producer. Lime is local in its action, the heat produced by it is conlined tocertainsectionsof the mines, while underlying the wliole length of the Comstock lode is that wbich canses the general heat, namely, the deposits of iron pyrites. ïlie hottest places in the mines are where tlie heat is generated by botli lime and pyrites; it is the heat of the linie added to the heat from nature's workshop below. The hot springs of Colorado may derive a portion of their heat from the decomposition of lime, but this is only a secon-lary cause. The great and first cause of heat in springs and mines is the deeomposition of iron pvrites nuisses of irou and sulphur. At Steamboat Springs and other places iiï this state, and at places in California, the heat is produced by the burning out or decomposition of iron pyrites. At Steamboat Springs the couise of the deposit of iron pyrites is northeast and southwest, the sameasthatof thegreat mineral bearing mines of the state. The line of active springs follows the course of this deposit, moving toward the northeast. At the southwest end are to be seon places where the deposit of iron pyrites and similar mincrals carrying large quantities of sulphur, has burned out and springa have died away. Theprocess of burning out is slowly moving toward the northeast. In 1860 the wiiter saw a now spring just stalling upthrough athickgrowth of grass in a bit of meadow land, far in ad vanee of the older and largerones, but on the same general line, well out to the northeast. The base metal deposit at Steamboat Springs has also the same dip as the Comstock, and is working east as well ia toward the north. By going froin ïalf to three quarters of a mile west of .he present active springs at Steamboat one rnay see just where the springs wereages ago, along near the pings or upper edgc of the deposit of pyritic xiatter. As the decomposiüon proceeded downward and custward along the dip of the deposit, the steatn and hot water l'ound or forced new vertical chanjiels of escape. Some of these openings are probably natural erevices, but the niajority are undoubtedly rents produced by the foree of steatn and pent up gases, Even on the Burface at Stemboat Springs are to be seen long rents froiu an inch or two to over a foot in wfdtfa that have a northeast and southwest course. In California soine of the hot springs are observed to be dying out at one ead of their line and advancing into new ground at the other. The mines of Europe and Mexico, which are coinparatively cold at great depths, are undoubtedly ages and ages older than the Comstock. The Comatock is probably the youngest mine in any part of the world that is now known or being worked. Here, down in our lower levéis, we are following close upon the heels of nature - getting well down into her workshop. . As to the heat geneniting power of sulphur and iron, those who desire to dosomay satisfy themselves. Tnke a few pounds of iron lillings, borings and drillings from a machine shop, wet them and mix tliem in a pound or two of sulphur, Uien tanip the mixture tlnnly into a hole in the ground - like a post-holc - covering witb two or three inches of dirt, and in a short time there vvill be seen a miniature volcano, the batch of iron and sulphur taking Bre simrtltaneonsly. The two ii'on freight boats now building at "Wyaudotte, lor the Goodrich Stearnboat Company, are to be nained the "Wisconsin umi Michigan. Theyare intended tonm betireen Milwaukee and (rand Haven, and will be constructed witli particular reference to breaking ice daring tlit' winter months. One of tlie boais is last approaching coinpletion, and will be launched by the lst of Seplember, and the other during Oetober. ïhey measure200 feetkeel, thirty-four feetbeam, foniteen f eet deptli of hold, and are calculated to carry tbout 1,200 tons eacb in thirteen feet of water. They will be iuniished with large and powerf ui compound engines, and steel boilers measuring ten i'eet in diametei' and seventeen feet six inches long. Like all iroii boats, these win havo a false Hoor, raised twenty-two inches above Ui6 boltoin floor, and will be supplied with three large bulkheads, which can at anr time be iilled with water for billast. A good sized centrifugal pump to force tliese bulkheads will be kept on board, and it can also be used effectively in case of either vessel leaking. Both boats will have an average speed of Ihirleen miles per hour. They will have full length cabins, with accommodations for 120 flrst-chiss passungers. The total cost of these model boats is estimated at $150,000 ench, when eompleted. It is better to hit the nail on the head twico than it is to hit the nail on the linger once. It rains three times as often ia Ireaud as it does in Italy. Old as the hills - Tlievalleys between Uiem. With tlie present inereased facilities, the Cliicago stock yarda can hándle 15(X) car-loids of stock in a day.