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Otago Daily Times, Issue 316, 24 December 1862, Page 6

•Death by Lightning at CARLSRirnB.--Tliis district was visited by a thunder storm on Friday eventnglast.e The lightning -was very iuivid. A"man eniployed by Mr Courtenay, of Carlsruhe,i\vas in a field at a fence; the electric fluid, attracted-by the post, shattered Into a thousand splinters, and struck the the, poor fellow deadiupon the spot; Ais name was Nicolo Battist3, aSwiss.^Aii inquest was i Id upon the - body.- ;! The1 jtist ', mortem examination sliowed that the whole of owe side! had been efibcted by the flued^-Alt was :uniformly: diswiered, having ra^ purple hue; ■ i: A^lUtlf child ,I?h6 wi^istandiiig within & few yawls of^b^at&s^

JKEW-- QUARTZ <3RUSHINO MACHINE; A recently invented mill, for crushing quartz and other substances, lias been erected at Sir Ainsworth's store, in York-street. The machine, which is the invention of Mr Hall,of Maitlaud, is now extensivel}' used for quartz crushing in California, but has not before been* introduced into this colony. A patent has heen obtained for the machine, under the name of " Hall s Pulveriser," and has been disposed of to Messrs Ilobblewhite and Co, of Pitt-street, The principal portion of the apparatus consists of a drum or shell, of past iron, about three and a half feet in diameter, and eight or nine inches in width. Through the centre of the drum a steel shaft passes, having s'x flat sided arms reaching to within about two inches of the periphery, or rim, which has a succession of square -edged projections on its inner side. The material to be crushed is put into the drum on one side, and as the arms are carried round with great velocity it is thrown between these and the corrugated edges of the drum, and by the violence of the propulsion quickly pounded and rendered into a fine dust. On the opposite side of the drum to that where the material is received, there is a tube communicating with a small chamber ; the rapid motion of the arms causes them to act as a centrifugal blower, and to send through the tube every particle of the powder. The practical efficiency of the machine has been proved by the extreme fineness of the flour deposited in the chamber. The material tested was some of the argentiferous quartz from the Meruya mines, and portions of the powder have been taken away to be tested. At the first trial of the machine 48£ lbs. of quartz were pulverised inl^ minutes; at the second trial, 56 lbs. were crushed in l£ minute ; and at the third trial, 56 pounds were crushed in 1 minute 35 seconds. It is calculated that the machine would pulverise a ton of quartz in its raw state within an hour; but that if the quartz were calcined a ton and a half might be crushed in that time. The machine is driven by one of Garrett's portable engines of eight horse power, lent by Mr Ainsworth for the purpose. It only needs, however, a fourhorse- engine to drive the machine at the required rate ; it might indeed be worked by hand. The essential difference between "Hall's Pulveriser" and other quartz -crushing machines is, that it reduces the material by means of contusion instead of by grinding. It has an advantage over other machines in being smaller in size, simpler in construction, in being more easily worked, and in being less expensive. The fineness of the product depends entirely on the velocity with which the miil is worked, and on the position of the pipe for the exit of the ground material, and a high or a low velocity can be applied, to suit the nature pf the material to be crushed. Although primarily intended for the reduction of gold quarts, the mill is capable of being used for grinding all sorts of grain and other substances, such as loaf-sugar, bark, zinc, drugs, white lead, fire-brick, &c, and for purposes of disintegration generally. The mill is stated to be particularly adapted for the grinding of wheat, as it would do away with the rubbing of the flour, . The prospectus of " Hall's Pulveriser" gives the following analysis of the action of the machine:— ." For a clear understanding of the action of this instrument, it will be necessary to analyse some of the natural laws which are brought into requisition during its vise. The difference between absolute momentum and continued force is well understood, but when the momentum is carried up to unusual speed, it is claimed that new actions and functions are developed, which are not to be found in the trip hammer or usual means of exercising momentum. -' Suppose a piece of gold quartz be thrown intp the atmosphere and during its descent to be stricken by a sledge-hammer travelling at the rate of twenty thousand feet per minute— it is claimed that the action will not be merely to break the gold quartz into fragments, but to surprise the cohesive power of the mass, and thus for an instant of time to do away with that property, rendering the mass representing smoke or the finest possible division of matter. And this claim we consider, can be rendered understandable by a clear illustration of what constitutes cohesion, and also by a developement of anew function which may be thus expressed. A body in motion is said, in common mechanical parlance, 'to have a power as a projectile equal to its weight multiplied by its velocity.' It may be said, with equal truth, that the hardnesss of a body in motion is equal to its harduess multiplied by its velocity. Thus, it is wellknown that a candle may be thrown from a gun through an inch plank, while it is well known that a candle is much softer than a board. It is also well known that a disc of soft iron rapidly revolved will cut in two a bar of steel: indeed, any substance which, from its surroundings and peculiar configuration, can be passed with great velocity" is increased in its relative hardness. Let it be admitted, then, that with Hall's machine the moving arms may be made to reach the velocity claimed as necessary to surprise cohesion. If cohesion be examined as a property in matter varying in different substances, and suppose it to arise from the attraction of particles for each other, rather than from a hooklike form of particles interlacing each other, no difficulty will be found in comprehending the immense force necessary to sever it. Thus, a cubic inch of steel, (or an inch area of steel would be more proper in this case,) exercises tension at the rate of 90,000 lbs, when applied as continued force, and not as a momentum. If the rule be recollected that attraction is inversely as the squares of the distances, and then admitting that with an ordinary magnet the attraction exercised upon the keep at the distance of one inch is 1 lb, then at half-an-inch it will be 4lbs, at a quarter of an inch 16 lbs, at the eighth of an inch 256 lbs, at the sixteenth of an inch 65 y 536 lbs, at the thirty-second of an inch the square of that number, and so on at the same ratio, until at the point which is supposed to be actually in contact; it is no longer curious that the inch area should sustain 90,00 a lb, but rather that any amount of force which could be practically applied would draw it asunder, and were it not for that film of resistance described by Newton, it could not be separated. When a surface is attached by absolute momentum this film of resistance may be pierced, and although in ordinary use two billiard balls do not really touch each other, and therefore the polish is not destroyed, and the ball is not split, still with an increased amount of momentum both these effects will occur. As an illustration, suppose a polished anvil have placed upon it a piece of gold leaf, and you should put upon this any amount of continued force, it would not cause any amalgamation or other connection between the gold and the" anvil, and after removing the imjanging matter the gold leaf might be blown off; but if the gold leaf be stricken by a polished hammer so as to develope jnomentum at the point of contact, that point alone will be found to be permanently gilt, and if we scrape off the surface to three times the thickness of the gold leaf, we shall still find gold imbuing the metal. This is a well-known fact, and fairly illustrates that by absolute momentum the film of resistance maybe pierced, and certain metals may be forced into each other. Now, in the use of the arms of Hall's machine, it is claimed that absolute momentum and not continued force, is the form in which all the power is developed at the speed proposed. This momentum is sufficient, not only to do away with the film of resistance at the point of contact, but to surprise the cohesion of the particles, so that instead of breaking the mass l 5 into many pieces, it absolutely divides it into its ultimate particles; and there is a speed at

which chalcedony and gold quartz may be crushed by this machine, so that the powder resulting is so fine that when rubbed between the fingers it is soft like velvet, exhibiting no | grit or other proof of crystalline cr other con- ' tinuous structure; nor will the machine itself] be abraded during this action, foY so great is i the speed of the arms giving the momentum I that their hardness, as before explained, is in- I creased is the same ratio. Even the surface of these castings will not be abraded, while the substances they are impigned upon will be delivered from the machine in this finely , divided condition. '" All the former methods of crushing gold quartz'have failed in exhibiting all the° gold, from the absence of an entire division mechanically of the particles. This may be thus understood: a piece of pure gold' drawn across the surface of a hone leaves a yellow mark, and in many kinds of gold ores this graphiticlikemarkißto.be found percolating the mas?, and when divided by washing, de" spite all methods yet pursued, it pasles off with the water. Indeed, this finely divided gold will float a month on the surface of water without becoming wet on the upper side of the particle, or, in other words, without sinkng, and it is therefore lost. Many specimens of gold quartz contain a much larger amount of gold than can be separated from them after what is usually called thorough grinding by washing; and the same defects, from the same reasons, occur during the attempted modes of amalgamation. When the quartz, however, is crushed by Hall's machine at its greatest velocity of action, every graphic indication of the gold is caused to appear upon the surface of particles, and, therefore, may be removed by ordinary amalgamation. It has been proven that ore crushed with this machine will yield a large percentage of gold, beyond the amount obtained by the usual methods." We believe that the mill will be at work at Mr Ainsworth's throughout this week. It is well deserving of the inspection of those who are interested in quartz-crushing machinery. S. M. Herald. • °