In his Report for the year 1845, the Com missioner of Patents says :—” The extraordi nary art of anastatic printing has been patent ed in this country by foreigners, and, as tar as ascertained, has been practised with success in the city of London. The patent was granted for the process, and not, of course, for the re sult or principle. The credit of the discovery and of the first successful production of copies from an engraving or other printed work, be longs to one of our own countrymen, Mr. Jo seph Dixon, of Mystic, Conn., (now of Jersey City,) and according to the most creditable testimony, his results are far more perfect than any hitherto attained by others. Mr. Dixon has been for many years engaged in perfecting his art, and I can testify from per sonal knowledge of his success in this inven tion many years ago. But, as the office was not in possession of the details of his process, no reference could be made to him, and the patent was accordingly granted as above sta ted. Mr. Dixon's discovery is mentioned in a work entitled “ Science Applied to the Do mestic and Mechanic Arts, by Rev. Alonzo Potter, published in 1841, and in the same work is given a specimen of Mr. Dixon's printing." The monthly statement of the Philadeli- phia Mint shows the receipts of gold for No vember to have been $7,260,000 : the coinage $4,990,543. The total receipts for the past eleven months are set down at $47,699,354.Bdmtiik %%mxica\x, Machinery and Tools aa they are..--The Steam Engine. (Continued from page 99.) Land Engines—The constructor of land engines has more opportunity to develope the economical working of steam than the ma kers of locomoti ves and engines for steam ves sels who are cramped by the restrictions im posed upon them from the cheracter of their work. 'It may be asked,—by what standard is the excellency of a statltonary engi'1e to be determined? To this the answer is plain, it is determined chiefly by the amount of duty performed by a given quantity of fuel,—a cir cumstance influenced greatly by the boiler, but also affected by the construction and ma nagement of the engine. Stationary engines are now generally non- condensing, the prima ry expense ibeing less, and the machinery more simple, although where economy of fuel is of great importance the condenser is still retained. It is a common mistake to suppose that a high pressure engine is necessarily non-con densing, a mistake which will be corrected by a knowledge that the expression “ low pres sure” is now applied to steam that a few years since would have been considered. far too high for a condensing engine. Thus 41bs. per square inch above the pressure of the atmosphere in British marine boilers was thought sufficient, whilst at present it is not unusual with them to use steam at 14 and even 16 lbs. per square inch. But stationary engi nes are worked at a much higher pressure, and too often the advantages derived from expansion are neglected, although it is when the steam is at a high pressure that the be nefits of expansion are most available. The engines used for the Cornish mines in England have attained some celebrity, owing to their economical working, the steam being expanded from about one- sixth of the stroke, when, by the evaporation of about one pound ,of water, they are capable of raising 120,000 lbs. one loot high; whereas, a low pressure engine, with the same evaporation, and steam cut off at one half of the stroke, raises only .13,000 lbs. the same height. Perhaps the best construction for a land engine, when it is de sired to use the steam expansively to its full extent is to admit the - steam freely into a small cylinder during the whole of the stroke, but on leaving this cylinder to allow it in gress into a larger one, where it expands be fore its escape into the condenser. The oscillating cylinder is much employed for small land engines, as it affords a cheap substitute for the slide valve, if formed in the usual manner, by which one of the gudgeons or trunnions is made td regulate the entrance and exit of the steam, while the other gud geon or trunnion can be employed to work the feed-pump. The favorite construction for land engines throughout the United States is that in which the cylinder is placed horizon tally on flat beds, on these latter are secured the guide bars, main plummer blocks, 'c. When this is not the shape, we generally find that compact form employed in which a ver tical cylinder is placed on a pedestal, while the cranks below are worked by side rods. Small portable engines for agricultural purpo ses are now being rapidly introduced, in which case the boiler generally is cylindrical with internal fire- place, and the engine placed on the top of the boiler which is fixed on wheels so as to be drawn by horses. The diameter of the cylinder is, in general, about 7 or 8 inches, and it has been found ad visable to en case the cylinder, steam pipe, and pump, either in the smoke-box, or some other part capable of protecting them from the frost. No part of the stationary engine has lately' been subject to more modifications than the governor, to supersede which a water-regula tor is now often used, a variation from the usual form of the governor was on exhibition at the last Fair of the American Institute, and was mentionep in our report at that time. It is otten also constructed in a rather original man ner, consisting of a single hollow ball encircled by a zone, there is an opening through the under side to admit an upright spindle, which is attached to the ball by a joint in its centre. One side of the ball and zone is heavier than the other, and consequently, when at rest or moving slowly, it hangs down, but when dri ven last the centrifugal for” of the heavy side overcomes its gravity, and the zone assumes nearly a horizontal position. When this is the case a small link inside the ball lowers the usual brass collar on the spindle, and thus shutsi oft part of the steam until the gravity of the ball overcomes the centrifugal force, when the throttle-valve will re-open. We have mentioned the efficiency of the Cornish pumping engines, and comparison shows many points of resemblance between them and the American engines for river steamboats, which latter are so renowned for their performance. The great width of our rivers has been favorable to the system of placing the machinery on deck, which has, by this arrangement, allowed the use ot a strong er boiler than is attainable when the engines are below. The striking peculiarities of the American boat engine are visible at the first glance : the trussed beam overhead, the long stroke, the large paddle-wheel, and particu larly the arrangement of the cylinder valves, all different from those of the sea-going ves sel. It is, however, remarkable that one of the most eminent English machinists has late ly departed from his usual practice, and has used, instead, the American system of valves in a marine engine of 400 horse- power. Nor is this, we believe, a solitary instance, the same arrangement having been also lately ap plied to one of the new steamers belonging to the English West India Steam Co. Some improvements on the ordinary double spindle valves have also been introduced by a modification of the double beat valve; this is intended to remedy the springing to which the former are occasionally liable. The mode in which the valves are woraed, is well known. There are two rock-shafts, one for moving the steam valves, and the other for the ex haust valves. These shafts are worked by separate eccentrics, and give motion to the lifting rods by means of projecting arms, an arrangement that admits of any desired expan sion, sometimes only one rock-shaft and ec centric are employed. The expansion is also trequently regulated by having a cut-off or ex pansion valve placed in the steam pipe like a throttle-valve. (To be Continued.)
This article was originally published with the title "Anastatic Printing"