Having traced back in a former article (page 198) the source of all motion and of all life on our planet to be the heat of the sun, the answer to the question as to the source of this heat, becomes of still greater importance than it has ever been. Considered from this point of view the solar heat is an enormous motive power, stored up when the solar orb was formed, by the very act of its formation, and now this power is gradually returning into space, carried forward by the radiation of the sun's rays; here and there this power reappears in the form of motion, on the surface of some planet where the conditions to this transformation are favorable. I attempted in the former article to point out that, as chemistry has taught how matter shows itself to us under the most varied forms, and undergoes the most surprising transformations in its properties, even so the modern investigations in regard to force have proved that, being nothing but matter in motion, force will show itself also under different forms, and also undergo astonishing transformations, from motion of masses to molecular motion, the last of which may be vibr * tory, rotatory, etc., and produce the phenomena of heat, elastic-city, etc. It has also been proved that just as matter is indestructible, so that not an atom can be created or destroyed by man, even so force (matter in motion) is indestructible, and that not the least trace of force can be created or destroyed by man ; and like as the universe contains a certain measured amount of matter, so also it contains a certain measured amount of force, which means that even as the sum total of all matter is a constant quantity, so also the sum total of all force or motion is a constant quantity. I wish now to point out how a modification of the nebular hypothesis of Laplace will explain consistently the origin of ihe sun's heat, in accordance to the present state of our knowledge in regard to the relation betwpn heat and force, and the convertibility of one into the other. Laplace supposed that all matter in the universe was once in a state of vapor,' or was a nebula, and that by cooling it had contracted, and thus by further contraction formed the s n, stars, planetary systems, etc. This hypothesis presupposes the previous existence of an enormous high temperature, as well as the existence of the matter, the loss of the heat by radiation, the contraction subsequent on cooling, etc. When we, however, accept nothing but the existence of matter and of gravitation urging this matter to coalesce in diverse common centers of attraction, and apply to this supposition our present knowledge of the change of apparently destroyed motion into caloric, Laplace's hypothesis is at once elevated into a theory, and we may accept that when matter, at first diffused in the universe, and, urged by gravitation, commenced to coalesce in different centers of attraction, and had there this motion destroyed by opposing forces (viz., matter falling in opposite directions), the visible motion of the masses had necessarily to be changed into molecular motion, viz., heat. When now we take in consideration the enormous amount of matter falling together, and the almost immeasurable distances through which it fell, and apply to it the rule proved by modern mechanics, that the falling of 760 pounds 1 foot, or 1 pound 760 feet, will produce one unit of heat, the number of units of heat produced at the formation of sun and planets must have been so immense that it takes thousands of millions of years to cool such large masses, raised to so high temperatures, by radiation, a process which has been going on in the planets, as is proved in regard to our earth by geology, and as also is going on at present, as we know in regard to our sun by daily experience. The old hypothesis of Herschel, still also copied in some of our school books, that the sun is a dark, cold, solid body, surrounded by a luminous atmosphere, is utterly disproved by the investigations by means of the most valuable inventions of our decade the spectroscope Indeed, this instrument has not only proved that the sun possesses a high temperature, but also that this high temperature is not the result of a permanent combustion, like the high temperature on our earth (excepting volcanic fires), and also that this temperature is so high that most substances solid on our earth are surrounding the globe of the sun as an atmosphere in the state of vapor, as some of our metals, iron, nickel, sodium, etc. The ideas here presented were fully developed by the writer three years ago, before the American Institute, New York City, in a series of three lectures on the universe, its past history, present condition, and its probable final fate, which lectures are found in the Transactions of the Institute for 1866. If, then, the law of gravitation is the sole source of the sun's heat, and also of our ocean tides, and the sun's heat the cause of all motion on our planet, we must come to the conclusion that the simple and single law of gravitation once acting mutually between particles of matter dispersed in space, is the primary cause of all other forces, and that all the complex actions of life and other motions on the surface of our earth, being traceable back to the simple law, are only gravitation in disguise. P. H. Vaindek Weyde, M. D. m -# -------------- Causes of Steam Boiler Explosions. It is certain that any information as to the circumstances of steam boiler explosions, even if it does not give the causes, is valuable. We copy a few remarks from the fourteenth half-yearly report of the Chief Engineer of the Midland (Eng.) Steam Boiler Inspection and Assurance Company, which may be of real use . " At the end of the year 1868, 1,103 boilers were under inspection, and 1,530 under assurance, making a total of 2,633. These boilers were used for the following purposes : 1,238 in collieries, 1,156 in ironworks, and 239 in mills of Various kinds The boilers were of the following general description : 2,205 fired externally, and 428 fired internally. "During the year, there have been made 11,900 inspections f boilers, 1,483 of which have been internal, and 1,361 in the flues, and 1,656 reports have been sent to the owners. The following brief epitome of the chief points referred to in these reports may be of general interest : " The point of first consideration is the general construction or repair of the boilers, and the arrangement of the flues. Many boilers have been taken out as not being fit for the required pressure. Some or these have been discarded because the plates were arranged lengthways in the boilers, producing in the weakest position, long, straight seams without any crossing of joints. In some cases this weakness has been increased, by the inside lap of each plate being so small, that the rivet holes were almost at the edge of the plates. The flat ends of boilers have been frequently found insufficiently stayed, especially were tubes have been removed, and it has been at times difficult to convince owners of the danger of this, although the ends have been shown to be bulged from weakness. Some few machine-made boilers have been found quite unfit for use, simply because the work was inaccurately done. There is no question, boilers can be well made by machinery, but if the work is placed carelessly, so that the plates do not meet, or the rivets are not struck fairly, the boiler cannot be made sound. Boilers are constantly noticed needlessly weakened in order to obtain the doubtful benefit of a dome, especially where the hole in the shell is its full diameter. One small boiler (9 ft. 6 in. by 3 ft. 6 in. 30 lbs.) was pierced with so many holes for fittings in one line on the top, that more than one-half the strength of the shell was lost. " Boilers of good design and safe proportions are frequently made insecure by injudicious alterations, Tubes are taken out without any compensation for the loss of strength, and stays or tie-bolts are allowed to get slack. This has been more particularly noticed in upright furnace boilers, where new bottoms have been made nearly flat instead of hemispherical, causing a new strain on the angle iron and on the old work. In a somewhat similar way, mischief is often done by altering the arrangements of the puddling furnaces, or by substituting large mill furnaces, so that the boiler is exposed to more heat than the metal can transmit, or the water convey away in the shape of steam, and the plates become injured. Sometimes the exact contrary is done, and a furnace is discontinued, and half a boiler is exposed to cold air, while the other is furiously heated, causing a new and unequal strain. " Sometimes internal tubes have been found forced out of the circular shape, for want of strengthening rings or other means of security. Manholes have been found in a dangerous state from want of guard rings, .the edges of the plates having perished or cracked, rendering it impossible to make a good joint, and the continual leaking has made the matter worse. Serious complaint has had to be made of some of the workmanship in repairs, by which boilers have been nearly ruined. " Corrosion has as usual proved a serious evil. Suspicion was entertained that corrosion existed on the side of a plain cylinder boiler (22 by 5 16 lbs.), from its peculiar position below the surface of the ground, and on the brickwork being removed, the plates were found so dangerously thin all along the side, that holes were knocked through them with a light hammer. Some boilers have worked a long time with a brick covering to prevent radiation, corrosion was suspected beneath, and on removing the covering, every plate was found so thin as to make them quite unsafe. The tops of some plain cylinder boilers were frequently found wet from the leaking of the fittings and feed pipes, and as it was known that this could not continue without causing mischief, examination was urged, and the most dangerous corrosion was found, in boilers which ought to have worked many years longer without repair. " A vast number of safety valves are found needlessly overloaded, while the steam gages are often out of order and inaccurate. As the gages become only gradually defective, the evil is not seen unless they are trusted long after they are incorrect. The habit of putting them on the steam pipes, where the pressure is always varying, causes them unnecessary wear. It is always best to have one attached close to each boiler, but where they must be in the engine house, or one has to serve for several boilers, they should be attached by separate pipes. It would often lead to great improvement, in the duty of engines working night and day, if the steam and vacuum gages were mf-registering." Poisonous Dyes. At a recent meeting of the Academie Imperiale de Medecine, M. Tardieu made a communication touching the poisonous action of some modern dyes. He reminded his hearers that M. Cerise had confirmed his former statements respecting the poisonous nature of coralline, by calling the attention of the Academie to a case of such poisoning produced by wearing socks dyed with this substance; and said further, that Dr. Despaull Ader had a marked case of the same kind, which, however, had not been published. Another case of a little girl who had suffered from the characteristic cutaneous eruption, brought on by wearing some garments dyed with coralline, of English manufacture, had been brought under his notice by Dr. Michalski, of Vierzon. These cases are examples of a special kind of poisoning, by means of a special poison coralline and are to be carefully kept distinct from other cases of a different kind, which M. Tardieu referred to. He mentioned that Dr. Viaud Grand-Marais, Professor in the Med ical School of Nantes, had met with a case in which the poison contained in a dyed shirt was not coralline, but magenta, the well-known aniline-red. The poison in this case was the arsenic contained in the magenta, so that, strictly speaking, it was an example of arsenical poisoning. M. Tardieu called attention to the well-known fact of the employment of arsenic in the manufacture of magenta, and remarked that, despite all processes of purification, this dye almost invarably contains arsenic. In order to facilitate the collection of information relative to poisoning by means of dyes, and to avoid confusion, M. Tardieu gave a brief resume of the distinctive chemical characters of the different organic red dyes to be met with in commerce. These dyes are six in number gar-ancine (madder), cochineal, murexide, carthamine, magenta, and coralline. The first three cannot be used in dyeing without a mordant; the last three are taken up by woolen or silk fabrics without it being necessary to employ a mordant. 1. Garancine (madder) is the most fixed of all the organic red dyes ; it is not altered by a solution containing three or four per cent of hydrochloric acid or of ammonia. 2. Cochineal is turned violet by ammonia, and, at the same time, communicates a bright violet color to the ammoniacal liquid. 3. Murexide is bleached by citric acid. 4. Carthamine is decolorized by a short boiling with a weak solution of soap (about one part of soap in two hundred of water is enough). 5. Magenta is decolorized by ammonia. 6. Coralline is not diminished in intensity by contact with alkaline fluids. It is dissolved off the fabric by means of boiling alcohol, giving a red liquid, which is intensified by ammonia or potash, a character which at once distinguishes it from magenta. At the same meeting of the Academie, M. Che valuer observed that the confectioners who had been in the habit of coloring bon-bons with magenta, had received orders to substitute some other dye for that purpose. Mr. Wanklyn, whose communications respecting, the dan gers of the modern dyes will be remembered, and wh was, we believe, the first to point out the danger of arsenical poisoning, by means of magenta-dyed underclothing, writes to us to say that a composite dye is now very much in vogue, consisting of magenta, tinted with some orange-coloring matter. This dye, a splendid scarlet, very much used for underclothing, is doubly poisonous, and exposes the unfortunate wearer to the risk of being poisoned by arsenjc, and the risk of being poisoned by an irritant orange dye. The Great Pyramid. The accurate measurement of the sides of the Great Pyramid, says the Public Ledger, is still attracting attention, and the result of the labors of the party of Royal Engineers of Great Britain, now engaged in this work, is waited for with much interest. The surveys, if correctly made, will settle many interesting points in reference to the units of lengths used among the ancients. Thus Herodotus states that the Egyptian cubit is equal to the Grecian cubit, and that the Great Pyramid has sides exactly five hundred Egyptian or Greek cubits in length, and covers exactly twenty-five arurse or Egyptian acres, the arura containing one thousand square cubits. Again, the Parthenon at Athens, according to other historians, gives the Greek units of length, and by modern measurements of this ancient building, the mean length of the Greek foot is 12.149 inches, and of the Greek cubit 18*224 inches. Multiplying the cubit thus ascertained by 500, the length of the sidfe of of the Great Pyramid should be 9,112 inches* The mean length of the side of the Pyramid as obtained by ex amining the structure itself, is calculated to be 9,110 inches, and thus a reasonably accurate standard of ancient measures has been fixed. The difficulty in the way of arriving at the true results is gieatly enhanced by the fact that the casing stones of the Pyramid have been removed. The sockets cut in the rock to receive the corner blocks still remain, and the calculations as to the actual width of the casing stones are affected by errors arising from this source. --------------* -------------- Fiber of Cocoannt Husks The method of converting cocoanut husks into useful fiber, is thus described in the Mechanics' Magazine: The shell, or outer covering of the nut, is first soaked in a tank of water kept warm by steam. When sufficiently soaked, the shells are conveyed to a hopper, through which they are fed to a crushing milf, which consists of two coarsely-fluted rollers, between which the shells pass and are crushed. They are removed thence to the fiber mills. Here the shells are drawn in between two rollers, behind which are arrangements for tearing away the finer fiber and leaving the coarser in the hands of the operator, who presents first one and then the other half of the shell to the action of the mill. The coarse fiber is then carried away and prepared for conversion into brushes and brooms. The finer portions of the fiber are removed from the mill, and undergo a process of final dressing. This is effected by feeding them through a hopper into a circular screen, in which an Archimedean screw rapidly revolves. The fine fiber is delivered at the mouth of the screen, while the dust and smaller particles of fiber are carried through the sieve. The fiber thus produced is used for making mats and matting; the siftings find a ready sale with florists and market gardeners, for manure. The sweepings and refuse are collected and burned under the boilers. Welding Powder. A powder of the following composition, recently patented in Belgium, is said to be very useful for welding iron and steel together. It consists of one thousand parts of iron filings, five hundred parts of borax; fifty parts of balsam of copaiva or other resinous oils, with seventy-five parts of sal-ammoniac. These ingredients are well mixed together, heated, and pulverized. The process of welding is much the same as usual. The surfaces to be welded are powdered with the composition, and then brought to a cherry-red heat, at which the powder melts,' when the portions to beunited are taken from the fire and joined. If the pieces to be welded are too large to be both introduced at the same time into the forge, one can be first heated with the welding powder to a cherry-red heat, and the others afterward to a white heat, after which the welding may be effected. Another composition for the same object, consists of fifteen parts of borax, two parts of sal-ammoniac, and two parts of cyanide of potassium. These constituents are dissolved in water, and the water itself afterward evaporated at a low temperature. ,---------------- ---------------- Liquefaction of Gases. Mr. Ladd has lately exhibited at the Royal Institution, London, a very elegant experiment, showing the liquefaction of gases by pressure. Three glass tubes, open at the bottom, containing cyanogen, sulphurous acid, and ammonia in their upper parts, and filled with mercury below, are inclosed in a strong glass cylinder filled with water. At the top of the cylinder is a small force-pump, which, when worked, drives more water into the cylinder, and forces the mercury, which acts as a piston up the tubes. As the mercury rises the gases are condensed, and now appear as liquids at the top. When the pressure is reduced by opening a stop-cock the liquids boil, and the gases speedily re* sume their normal dimensions. A Monsteb Blast. A blast of unprecedented magnitude was recently set off at Smartville, California. The tunnel in which the enormous charge of powder, no less than 1,200 kegs was placed, has been some time in progress. It was 570 feet in length, and undermined a mountain which it was desired to shatter for purposes of hydraulic mining. The charge was ignited by an electic wire, a romantic young lady being the one chosen to perform the task. The mountain was thoroughly shattered in the presence of thousands of people collected te see the novel sight. Improved Style of Two-WIieeled Velocipedes. Some time ago we intimated that the perfect velocipede was yet to be built; since then we have secured patents on a number of improvements, not possessed by any of their predecessors, and thus the point of perfection is being attained. The one represented in the accompanying engraving is well worthy the attention of velocipede riders and builders, for its simplicity of construction, cheapness of cost, ease of management, and adjustability for suiting the size and strength of the rider. The frame is of hollow pipe, the rear being a'complete circle in which the steering wheel rotates on its axis, the driving wheel running between the parallel bars of the front portion. The axle of this wheel passes through boxes secured to the parallel bars [by set screws, so it may be adjusted forward or back to suit the physique of the rider. The axle of the steering wheel runs in boxes secured to sliding bars curved to fit the inner diameter of the circular portion of the frame, thus allowing this wheel with its axle to perform an entire revolution within the frame on a horizontal plane. Its movements are controlled by means of rods attached at one end to ohe ends of the axle, and at the other brought together to the lower end of a lever directly under the rider's seat, the handle of which comes up in front of the rider, the fulcrum being on a cross piece between the rear portion of the parallel bars, serving not only that purpose but that of a brace. It will be seen from the figure that the guiding of the vehicle may be effected by one hand. The seat need not be so high as represented in the engraving ; it may be lowered until nearly to the level of the reach, which is the horizontal line of the axles. Such a vehicle is easily and cheaply constructed, and will operate with ease. The reach, which in the ordinary bicycle extends in an upward curve from the level of the rear s axle to the top of the driving wheel, is easily made, while in others its forging adds greatly i to the cost of the vehicle. In mounting the % ordinary two-wheeled velocipede the rider I must spring from the ground to a hight not easily reached by persons of obesity or of slug- 1 gish habits, and the danger of damage to both -rider and vehicle is greatly enhanced by hight from the ground. If overturned, this machine cannot fall upon the rider, as the circular formation of the rear portion forbids a complete inversion. The danger of overturning this machine is still further diminished by the weight of the rider being brought nearer the center of suspension, as his seat may be brought very near the horizontal line of the axles without preventing or interfering with the action of his legs. The ease of guiding is sufficiently clear by an examination of the engraving, where the rider is shown as using only one hand for this purpose. Patent pending through the Scientific American Patent Agency by C. E. McDonald, who may be addressed at Amsterdam, N. Y.