Volume 35 (1877) (426 pages)

Er) September 22, 1877.] MINING AND SCIENTIFIC PRESS 179 Procress. ls M ECHANICAL Captain Eads’ New Dredge. Captain Eads, the engineer of tho jetties in tho mouth of tho Mississippi, fonnd the dredging dovices whiek were availahlo unlitted for his work. Peculiar conditious which exist at tho month of the jetties render the use of no dredge boat which can bullet tho waves a neces. sity. Therefore he devised a dredyo of his own, and is now having it constructed at TPittsbury, Pa. Wo are enabled, by a description in tho American Manufacturer, to compile a few points on the machine: The principal difficulty which has interfered with the successful pumping of saud or silt from the beds of streams has arisen from tho ditliculty of proportioning the quantity of solid matter tothe voluino and velocity of tho stream which is mado to transport it. <A given volume and velocity of water through the suetion pipe is capable of sustaining in suspension a definite amount of solil matter. If too great an ainount of solid matter bo admitted into tho suction pipe, the stream is unable to abel the ox: cess, tho pipo becomes clogged, and tho pump ceases to throw vither water or sand, To remedy this ditticulty, the end of the suction pipe which rests upon the hottom of the rivor is curved into tho form of a ilat scraper, fonr feet in widtb, which is armed with a steel plato, vias a hit, which may ho foirly com. pared to tho bit in a earpenter’s plane. To preveut this hit froin taking too doep a eut iu tho sand, the end of the pipe is supported ou an ad. justahlo horizontal plate, which rests upou tho sand in advanco of the hit or scraper. To insure tho proper quantity of water entering the suction ipo with tho sand, the horizontal plate just descrthed forms the hottom of a water chamber into which the water is rceeived five feet above the scraper. The water is forced into the chainher by the atmospherie pressure resulting from tho vacuum created by the pump. The ond of the suetion pipe, therefore, is continually drawing iu n stream of sand four feet wide, aud n stroam of water of the same width, hoth eutering tozether immediately above the scraper; tho discharge of the water chamber being immediately over the stream of sand which is passiug in over the top of the scraper. The sernper is Neeaed to he inoved at a speed of from 10,000 to 15,000 feet per hone. By a very simple device the plate which separates tho sand and water as they enter into the end of the suction pipe is made adjustable, and as the whole end of the apparatus rests upon the plate on the bed of the stream, it is only necessary to raise tho scraper or lower it to alter the quantities of sand and water which aro being drawn iuto the pipe. The depth at which the scraper is eutting the sand is constantly known hy the operator, and ean be quickly altered so as to take in a stream of sand 12 inches deep and a streain of water four inches decp at the same moment, or these proportions cau be reversed so as to take in a stream of water 12 inches deep and of sand four inches deep, or the euttor can he raised so as to bring it completely ahove tho sand, in which event the suction pipe will receive nothing hut water. The eentrifugal pump in the Bayley is the largest one of the kind ever construeted in the United States, and isknown ag the Andrews cataraet pumpThe suction pipe is 27 inches in diameter, of one-quarter ineh wroughtiron. It is attached to the hull of the boat in a recess four feet wide, and oxtending from the stern 25 feet forward, The boat is huilt entirely of iron, and is considered a very superior job. It is about 200 feet in length over all, and is propelled by two horizontal high-pressure engiues, each 7 feet stroke and 21 inches diameter, turning wrought iron shafts and wrought iron wheels 28 feet iu diameter, The paddles are of wood, 11 feet long and 24 inehes wide. The hoat is surrounded hy an iron bulwark about five feet high and set back twoand a half feet from the side of the hnll. The tanks have an estimated eapacity of 1,000 tonsof dredged material and water. Two overllow gates are provided for the tanks, which allow the water to escape when they are filled to the overflow level, the sediment settling to the bottom. The pumpis esti mated to he eapable of throwing 3,000 harrels of water per minute. Tue Resistance or Surps.—Mr. William Froude, at n late meeting iu London, read a highly scientific but most interesting paper, the object of which, says /ron, was to show the effect produced on the resistance to a ship’s motion by the lengtheuiug or shorteuing of the flat middle hody hetween the how aud stern. The results were based upon experiments made at Chelson Cross with models having the same ends, hut different lengths of parallel body inserted amidships. By separatiug the effeet o1 the frictional skin resistance, which was_proportional to the wetted surface, he showed that the iucrease or diminution of the power required to propel a ship, in consequence of the alteration of the length of the parallel body, depeuded very largely on the coineidcuce, or want oi coiueideuce, of the wave-crests traveliug along. side the ship witb tho points at which the reduetion of breadth hy the fine lines began. When this diminution coincided with a waveerest there was no loss but rather no gain of speed, while wheu it coincided with a wavehollow, the loss of speed, or increase of resistance, was considerable. Hints on Joining. In ‘‘ Andrews’ Guide to Chureh Furuishing ” are some hints for the fine carpentry of church interiors, which may apply just as well to other branehes of tasteful joiuing: The main stay of constructive woodwork is the mortise and tenon. <A piece of woodwork which can bo put together without glue, nails or serews, and serves its purpose, is on ideal work of construetion; hut this is not always vossihle. Another principle of construction is that overy piece of wood should he so placed that it can swell or shrink without injuring itself or displacing nny other piece. This is maintained in an ordinary pancled door, provided no moldings are inserted, Still another principle is that miter. joints should be avoided, whether for molded work or not, for the roason that shriukago causes nll iiters to open, No piece of wood shoul! be used nnless tho straight grain of the wood van be soen throngh its full longth in one oe Inserted moldings should be nvoided as ar as possiblo; and all moldings for panel: work should be worked on tho styles and rails. It is a general prineiple, obsorved in the best medieval joinery, that all moldings on rails which are horizontal should butt against the styles; and that styles should be either plain or shonld havo moldings stopped before reaching the joints with the rails. In prnetice, all rail moldings may be worked the wholo length of the stuff used; and if muntius (which are the middle styles) aro used, the moldings may be cut away to tho square wood hefore the mortiso is eut which is to receive the tenon of the muntin. Thus the moldings will hutt ngainst the square sides of the muntin. Al] the parts for a door thus made ean now be got out by machinery, and the door will be fully eoustruetive in every sense of the word. There is no obstaclo to this iu the way of eost. The dovetail is a constructive dovice; and the dowel is admissihle in places as a substitute for the mortise and tenou. Tongue and grooving is a legitimate device, both for ends and sides of boards. Beveling the edges of the pieces thus joined is better than beading. The hest way to construct large panels is to make them of narrow strips, tongue and grooved, aud heveled at the joining edges. Sueh pancls will never “draw.” The shrinkage will be divided between all the jeiuts. Solid table-tops should never he fastened with glue or screws, hut should be secured with buttons fastened to the under sido of the top. which travel in grooves cut in the framework to allow for expansion and shrinkage. ‘Theso are hut few of the principles to be ohserved in doing the best woodwork. In all kinds of lumber the heart should he rejected. All hoards cut on a radius from the center to the periphery of a tree will remain true, while all others have a tendency to warp or crack, The first are called ‘‘ quarter-sawn.” It is a peculiarity of oak that the best grain is found in quarter-sawn boards. It is only in these that the ‘‘silver-grain” is seen, This consists of a rihbon of very hard substance which grows out from the center of the treo. It is for this reason that onk is the most enduring wood; it has a grain two ways. All woods erack in the direction of a radius from the ceuter. Quarter-sawn oak eannot erack. Srrtz TALKING KEELEY.—The Philadelphia papers are still talking the Keeley motor language just as vigorously as though the world had not pronounced it meaningless. It sounds like old times to read the following: ‘The operation merely consists, then, in a motiou of the lever already described; aud certainly last night its results were wonderful, nnd demonstrated that the power is made from hydrant water and ordinary air, no chemicals about it, and it will drive an engine and transmit power. The vapor passes from the machine into a stcel shell and iuto acondensing apparatus, whence it goes to a small tuhe and thence to the engine. The valves were all opened to show the machine was clear, air introduced, and the lever was lifted, the first move showing 1,750 pounds pressure on the gauge to the square inch; and though the chamber for condensing was open, the current did not hlow out a match held over it. With six and one-half pounds air pressure the gauge indieated 5,200 pounds to the inch, and then 6,700 on the third trial, On the fourth, it lifted a large lever (weighed) registcring 5,000 pounds dead weight. The vapor was turued into an explosion echamher, and the cap flew off with a report like a rifle, frightening half those present; and lastly, a five-horse power engine, with three-fourths-ineh stroke and 24-inch fly-wheel, was driven at 680 revelutious to the minute. The skeptieal engineers were convineed that the power was there, and that it conld be applied. Che present machine cost $60,000. One of the engineers said they had produced 144 vaccum on one experiment; and 15 is perfect, as all engineers know. A puhlie test will be given shortly.” The last sentence is especially familiar. A Mecnayte’s Lanor anp Rewarp.—Palissey, a French surveyor of the fifteenth eeutury, was seized with an ardent desire to discover the Chinese mode of enamelling porcelain. In the pursuit he wasted his substance, hurut tis furniture as fuel for his furnace, and even sold his clothes. But be suceeeded, and made a large fortune. At 90 he died in the inquisitiou. Revivine.—All the mills of the Allentown Rolling Mill Company are at present running with a full compliment of hauds, having received a large order which is to be filled within the next two or three weeks, a ~3 SCIENTIFIC Procress. Mineral Growth Again. A few months ago we had 4 paragraph copcerning tho *‘Growth of Minerals,” a subject with which Mr. Readwin perplexed tho young Royal Mineralogical Society of Kuglaud. Wo read uow, in Mnglish papers, tbat this gentleman, since his last paper en this curious subject, has visited tho museums of Copenhagon, Stockholm, Christiana, Kongsberg and Loudon, is search of corroborative evidenco of resent mineral growth at ordinary temperatures un lee ordinary conditions. He took some of his hest examples with bim, and submitted them to many eminent mincralo.ists. The silver specimens at Copenhageu, for size, variety and beauty, surpassed all others, prohably, in tho world. The silver growtlis, out of ealcitc, epidote, fluor nud argentite, were almost numberless, Somo were old, others recent, and a few even infantile. He likewise found argentite ond clevtrum growths; the latter both out of quartz and pyrites, and including some very bright and positively very recent. Bian growth was also observed, and indications of reeent gold growth. The Stockholm collection had the reputation of heing in part the oldest in the world. There were many Kongsherg silver growths, moreor less tarnished, of great size and beauty, and some small ones of recent origiu; also tarnished eleetrum growths, a few eomparatively bright. At Christiana there were receut eopper growths out of fluor, foliated electrum growths out of quartz, and silver poe out of Kongsberg argentite. At Kongserg there was the most variedly interesting eolleetion of silver specimens it was possible to see, aud silver growths in nhundauce, including flat plates of silver growiug at the edges. A the British museum were n few small electrum growths, whieh ho believed were recent. He added a list of his chief ‘home growths” since May 5th, some of which he described as of a very remarkahle character. A Deez-Sea Sounder, At the recent meeting of the British Associatiou, Sir William Thompson deserihed an apparatus he had invented to make deep-sea soundings, not with a view to exploration, but for ordinary purposes of navigation while a ship was at fullspeed. A glass the, filled with air, was hermetieally sealed at tho top, hut opened at the hottom, and prepared with red prussiate of potash. It was placed into a brass tuhe, which was elosed at the bottom, hut allowed the free ingress and pressure of water from ahove. The hrass tuhe was partially filled with sulphate of tron, and wherever this iron came into eontact with the interior of the glass tube it turned into a Prussian hlue. The pressure of the water compressed the air, aud forced the sulphate of iron up the glass tuhe, according to the depth to whieh it deseended. The glass tube, partof whieh retained its original eolor, was then measured on a scale, and thus the depth of the sounding was indieated. For the purpose of being lowered into the sea, the tubes were attached to the end of a long piece of pianoforte wire, whieb weighed ahout 14 pounds per mile, and was capahle of hearing a strain of 220 pounds, At the extrenie end a 22-pound sinker was fixed. The ahsence of any friction from the wire facilitated rapidity both in sinking and hauling in, Some tuhes were exhihited which had been reeently used in taking soundings on hoard the White Star steamers Britannic and Germanic, during a voyage to New York and hack. The soundings were made when the sbips were going at full speed, at depths varying from ae 100 fathoms, and were perfeetly successhi, Tue Fiusu or Frvrrs.—It is generally supposed that tbe flcsh of the fruit provides the first food for the germinating plants of its seeds. Such, however, remarks the J/ownal of Chemistry, is not the ease, for here, as in other eases, the first nourishment is drawn from the seed alone. The flesh of the fruit hears no relation to the emhryo; it is a kind of outcast suhstance or excretion of the plant. In most of our cultivated fruit trees, too, the great mass of this flcsh is the result of cultivation. Thus, wild cherries possess so little flesh that they do not repay the trouble of plucking. Iu the mountains of Pontus grapes arc fouud so small that they are uot worth cating; and the wild apricot, and often, likewise, the wild peach, possess no flesh at all, the former, indeed, heing. like a leathery two-valved capsule. The flesh of the fruit of most of our cultivated fruit trees is analogous to the enlarged roots of the turuip and beet, and similar plants, and is simply the product of eultivatiou, which is much sooner lost again under neglected eireumstances than it was originally artitically produced, One of the most able Freueh hotauists, Professor Lecog, of Clermont Ferrand, instituted numerous experiments with various wild plants to induce then to form fleshy roots, aud he was almost invariahly successful. Just as it is the task of the agrieulturalist to increase the volume of his roots, so it should he the aim of the fruit gardener to increase the flesh of the pome, stone, herry fruits, and the substances stored up in the cotyledons of nut fruit. Praticar Ixstrection.—Tho tron Age says that auybody with whom there yet lingers a doubt whether summer schools of science may not niean pienics and n good time generally with a few scraps of learning by way of a sandwich, may bo reassured hy the actual hard work rea of certain students belouging to the School of Mines, Columhin College. The students referred to were 12 volunteers from the elass of ‘78 in tho department of eugineering, of whieh W. P. Trowbridge is Professor in charge; Henry 8. Munroe being assistant Professor, with this summer school under his immediate eare, Last mouth the 12 went to Drifton, a town in Luzerne county, Pa., and there were set at work in n coal mino—the actual work of the miners, handling o pick, drilling tho blast holes, loading the cars and the like. Among tho lighter work required of them were tho various constructions ueeded iu tho mino for supporting or lining tho openings, and similar details of ordinary mining labor, Several days were thus spent, the proprietor of tho mine, Mr. E. D. Coxe, and the regular miners in his employ, all taking a hearty interest in the scheme. Each of the studeuts was afterward requirod to furnish drawings and an essay from tho nates taken during their labors. The experiment in education is regarded as highly suecessful. AmeRicaN Pianrs ABroap.—M. Boreau, in a paper read hefore n Freneh scientitic sueicty, yives some curious instances of tho rapid distribution of certain foreign plants through the medium of water. The Panicum diyitarin, an American grass, first diseovered near Bordeaux in 1824, has spread widely in tho neighhoring departments, and has got as far south as Tounlouse. Anvther grass from southern elimes, the Stenotaphrum Americanum, is spreading its powerful roots in the sands at the mouth of the Adour. The Anacharis Canadenis has invaded the lakes and rivers of Euglaud, Scotland, Belgium, Holland and Germany. In Belgium aud elsewhere drains have heen rendered usele s, and eanals have been completely obstructed by these plants; and in many large sheets of water it suffers no vegetable life hut its own to exist. Since 1871 this formidable strangor has been gaining a foothold in Frauce; it has heen found on the outskirts of Brest, and it swarms in the waters of the Paris parks, Auother plaut of the same family, the Stratiotes aloides, intro. duced in 1828 in the neighborhood of Mans, has followed the course of the river Sarthe, and abounds in the neighboring lakes. Fiurp Carsonre Acrp in Rocxs.—The eommittee appointed by tho British Association “for investiug the conditions under which Jiquid carbonic exists in rocks aud minerals,” recently reported that, according to the method of determining the exact temperature at which earbonic acid in the eavities of rocks and miuerals beeame gaseous, the temperature known as the ‘‘critieal point,” at whieh Huid carbonie acid was found, was 39.92° Centigrade. The acid was found to be eontained in minute eavities of the rocks and minerals, and experiments had heen tried-upon sapphires, garncts, and other precious stones, aud the result had heen the discovery in these of earbonic acid. A curious fact had also been ascertained—i, e., that certain’ bubbles in the fluid cavities approached heat, whilst others reeeded from it, The ehanges of the earhouic acid from gas to liquid and from liquid to gas were found to be produeed hy the hightening and lowering of the temperature; atl in some of the cavities neither the gaseous or liquid form of the acid was to be found, the cavities being filled simply with water. Mr. Rusktn’s Capiner.—The minerals and precions stones in the museum at Walkley now form a collection of marvelous heauty, aud aro almost as varied as they are numerous. They are being arranged hy Mr. Ruskin in 20 groups namely, silica, oxide of titanium, oxide of iron, alumina, potassa, soda, magnesia, caleium, glueiua, flourine, carhon, sulphur, phosphorus, tellurium, urauium, tin, lead, copper, silver and gold. The founder of the institution, in his “Deucalion,” informs us that ‘‘the mineralogieal collection is fully descrihed and explained in the catalogue, so that auy young people may begin their study of it without diffieulty, and so chosen and arranged as to he eomprehensihle by persons who have not time to make themselves masters of the science of chemistry, but who may desire some aceurate acquaintance with the aspeets of the principal minerals which compose the world;” also, that ‘‘every one of the specimens is chosen for some specialty of character, and the points eharactcristic of it ure descrihed in the catalogue.” CHLOROPHYLL, or the coloring matter of plants, has been found by M. Fremy (as our readers may kuow) to eonsist of two principal eonstituents: one yellow, and ealled by lin phylloxanthin, and tho other a dark hluish-green, whicb he ealls phyllocyanic acid. Having furtber inquired into the manner in which tbe substances oceur in the orgauie tissue, he concludes that “the eoloring matter of leaves is a mixture of phyloxanthin and phylloeyauate of potash. Tue electrical illumination of the Lyons railway station it being completed. They are now usiug twelve electric lamps. This number will be enlarged successively to twenty-four lamps, fed with one light-producing and one light-distrihuting machiue. It is helieved that twenty-two horse power will give a power of 2,400 gas-lamps, usmg 100 liters each per hour.

Er) September 22, 1877.] MINING AND SCIENTIFIC PRESS 179 Procress. ls M ECHANICAL Captain Eads’ New Dredge. Captain Eads, the engineer of tho jetties in tho mouth of tho Mississippi, fonnd the dredging dovices whiek were availahlo unlitted for his work. Peculiar conditious which exist at tho month of the jetties render the use of no dredge boat which can bullet tho waves a neces. sity. Therefore he devised a dredyo of his own, and is now having it constructed at TPittsbury, Pa. Wo are enabled, by a description in tho American Manufacturer, to compile a few points on the machine: The principal difficulty which has interfered with the successful pumping of saud or silt from the beds of streams has arisen from tho ditliculty of proportioning the quantity of solid matter tothe voluino and velocity of tho stream which is mado to transport it. <A given volume and velocity of water through the suetion pipe is capable of sustaining in suspension a definite amount of solil matter. If too great an ainount of solid matter bo admitted into tho suction pipe, the stream is unable to abel the ox: cess, tho pipo becomes clogged, and tho pump ceases to throw vither water or sand, To remedy this ditticulty, the end of the suction pipe which rests upon the hottom of the rivor is curved into tho form of a ilat scraper, fonr feet in widtb, which is armed with a steel plato, vias a hit, which may ho foirly com. pared to tho bit in a earpenter’s plane. To preveut this hit froin taking too doep a eut iu tho sand, the end of the pipe is supported ou an ad. justahlo horizontal plate, which rests upou tho sand in advanco of the hit or scraper. To insure tho proper quantity of water entering the suction ipo with tho sand, the horizontal plate just descrthed forms the hottom of a water chamber into which the water is rceeived five feet above the scraper. The water is forced into the chainher by the atmospherie pressure resulting from tho vacuum created by the pump. The ond of the suetion pipe, therefore, is continually drawing iu n stream of sand four feet wide, aud n stroam of water of the same width, hoth eutering tozether immediately above the scraper; tho discharge of the water chamber being immediately over the stream of sand which is passiug in over the top of the scraper. The sernper is Neeaed to he inoved at a speed of from 10,000 to 15,000 feet per hone. By a very simple device the plate which separates tho sand and water as they enter into the end of the suction pipe is made adjustable, and as the whole end of the apparatus rests upon the plate on the bed of the stream, it is only necessary to raise tho scraper or lower it to alter the quantities of sand and water which aro being drawn iuto the pipe. The depth at which the scraper is eutting the sand is constantly known hy the operator, and ean be quickly altered so as to take in a stream of sand 12 inches deep and a streain of water four inches decp at the same moment, or these proportions cau be reversed so as to take in a stream of water 12 inches deep and of sand four inches deep, or the euttor can he raised so as to bring it completely ahove tho sand, in which event the suction pipe will receive nothing hut water. The eentrifugal pump in the Bayley is the largest one of the kind ever construeted in the United States, and isknown ag the Andrews cataraet pumpThe suction pipe is 27 inches in diameter, of one-quarter ineh wroughtiron. It is attached to the hull of the boat in a recess four feet wide, and oxtending from the stern 25 feet forward, The boat is huilt entirely of iron, and is considered a very superior job. It is about 200 feet in length over all, and is propelled by two horizontal high-pressure engiues, each 7 feet stroke and 21 inches diameter, turning wrought iron shafts and wrought iron wheels 28 feet iu diameter, The paddles are of wood, 11 feet long and 24 inehes wide. The hoat is surrounded hy an iron bulwark about five feet high and set back twoand a half feet from the side of the hnll. The tanks have an estimated eapacity of 1,000 tonsof dredged material and water. Two overllow gates are provided for the tanks, which allow the water to escape when they are filled to the overflow level, the sediment settling to the bottom. The pumpis esti mated to he eapable of throwing 3,000 harrels of water per minute. Tue Resistance or Surps.—Mr. William Froude, at n late meeting iu London, read a highly scientific but most interesting paper, the object of which, says /ron, was to show the effect produced on the resistance to a ship’s motion by the lengtheuiug or shorteuing of the flat middle hody hetween the how aud stern. The results were based upon experiments made at Chelson Cross with models having the same ends, hut different lengths of parallel body inserted amidships. By separatiug the effeet o1 the frictional skin resistance, which was_proportional to the wetted surface, he showed that the iucrease or diminution of the power required to propel a ship, in consequence of the alteration of the length of the parallel body, depeuded very largely on the coineidcuce, or want oi coiueideuce, of the wave-crests traveliug along. side the ship witb tho points at which the reduetion of breadth hy the fine lines began. When this diminution coincided with a waveerest there was no loss but rather no gain of speed, while wheu it coincided with a wavehollow, the loss of speed, or increase of resistance, was considerable. Hints on Joining. In ‘‘ Andrews’ Guide to Chureh Furuishing ” are some hints for the fine carpentry of church interiors, which may apply just as well to other branehes of tasteful joiuing: The main stay of constructive woodwork is the mortise and tenon. <A piece of woodwork which can bo put together without glue, nails or serews, and serves its purpose, is on ideal work of construetion; hut this is not always vossihle. Another principle of construction is that overy piece of wood should he so placed that it can swell or shrink without injuring itself or displacing nny other piece. This is maintained in an ordinary pancled door, provided no moldings are inserted, Still another principle is that miter. joints should be avoided, whether for molded work or not, for the roason that shriukago causes nll iiters to open, No piece of wood shoul! be used nnless tho straight grain of the wood van be soen throngh its full longth in one oe Inserted moldings should be nvoided as ar as possiblo; and all moldings for panel: work should be worked on tho styles and rails. It is a general prineiple, obsorved in the best medieval joinery, that all moldings on rails which are horizontal should butt against the styles; and that styles should be either plain or shonld havo moldings stopped before reaching the joints with the rails. In prnetice, all rail moldings may be worked the wholo length of the stuff used; and if muntius (which are the middle styles) aro used, the moldings may be cut away to tho square wood hefore the mortiso is eut which is to receive the tenon of the muntin. Thus the moldings will hutt ngainst the square sides of the muntin. Al] the parts for a door thus made ean now be got out by machinery, and the door will be fully eoustruetive in every sense of the word. There is no obstaclo to this iu the way of eost. The dovetail is a constructive dovice; and the dowel is admissihle in places as a substitute for the mortise and tenou. Tongue and grooving is a legitimate device, both for ends and sides of boards. Beveling the edges of the pieces thus joined is better than beading. The hest way to construct large panels is to make them of narrow strips, tongue and grooved, aud heveled at the joining edges. Sueh pancls will never “draw.” The shrinkage will be divided between all the jeiuts. Solid table-tops should never he fastened with glue or screws, hut should be secured with buttons fastened to the under sido of the top. which travel in grooves cut in the framework to allow for expansion and shrinkage. ‘Theso are hut few of the principles to be ohserved in doing the best woodwork. In all kinds of lumber the heart should he rejected. All hoards cut on a radius from the center to the periphery of a tree will remain true, while all others have a tendency to warp or crack, The first are called ‘‘ quarter-sawn.” It is a peculiarity of oak that the best grain is found in quarter-sawn boards. It is only in these that the ‘‘silver-grain” is seen, This consists of a rihbon of very hard substance which grows out from the center of the treo. It is for this reason that onk is the most enduring wood; it has a grain two ways. All woods erack in the direction of a radius from the ceuter. Quarter-sawn oak eannot erack. Srrtz TALKING KEELEY.—The Philadelphia papers are still talking the Keeley motor language just as vigorously as though the world had not pronounced it meaningless. It sounds like old times to read the following: ‘The operation merely consists, then, in a motiou of the lever already described; aud certainly last night its results were wonderful, nnd demonstrated that the power is made from hydrant water and ordinary air, no chemicals about it, and it will drive an engine and transmit power. The vapor passes from the machine into a stcel shell and iuto acondensing apparatus, whence it goes to a small tuhe and thence to the engine. The valves were all opened to show the machine was clear, air introduced, and the lever was lifted, the first move showing 1,750 pounds pressure on the gauge to the square inch; and though the chamber for condensing was open, the current did not hlow out a match held over it. With six and one-half pounds air pressure the gauge indieated 5,200 pounds to the inch, and then 6,700 on the third trial, On the fourth, it lifted a large lever (weighed) registcring 5,000 pounds dead weight. The vapor was turued into an explosion echamher, and the cap flew off with a report like a rifle, frightening half those present; and lastly, a five-horse power engine, with three-fourths-ineh stroke and 24-inch fly-wheel, was driven at 680 revelutious to the minute. The skeptieal engineers were convineed that the power was there, and that it conld be applied. Che present machine cost $60,000. One of the engineers said they had produced 144 vaccum on one experiment; and 15 is perfect, as all engineers know. A puhlie test will be given shortly.” The last sentence is especially familiar. A Mecnayte’s Lanor anp Rewarp.—Palissey, a French surveyor of the fifteenth eeutury, was seized with an ardent desire to discover the Chinese mode of enamelling porcelain. In the pursuit he wasted his substance, hurut tis furniture as fuel for his furnace, and even sold his clothes. But be suceeeded, and made a large fortune. At 90 he died in the inquisitiou. Revivine.—All the mills of the Allentown Rolling Mill Company are at present running with a full compliment of hauds, having received a large order which is to be filled within the next two or three weeks,

a ~3 SCIENTIFIC Procress. Mineral Growth Again. A few months ago we had 4 paragraph copcerning tho *‘Growth of Minerals,” a subject with which Mr. Readwin perplexed tho young Royal Mineralogical Society of Kuglaud. Wo read uow, in Mnglish papers, tbat this gentleman, since his last paper en this curious subject, has visited tho museums of Copenhagon, Stockholm, Christiana, Kongsberg and Loudon, is search of corroborative evidenco of resent mineral growth at ordinary temperatures un lee ordinary conditions. He took some of his hest examples with bim, and submitted them to many eminent mincralo.ists. The silver specimens at Copenhageu, for size, variety and beauty, surpassed all others, prohably, in tho world. The silver growtlis, out of ealcitc, epidote, fluor nud argentite, were almost numberless, Somo were old, others recent, and a few even infantile. He likewise found argentite ond clevtrum growths; the latter both out of quartz and pyrites, and including some very bright and positively very recent. Bian growth was also observed, and indications of reeent gold growth. The Stockholm collection had the reputation of heing in part the oldest in the world. There were many Kongsherg silver growths, moreor less tarnished, of great size and beauty, and some small ones of recent origiu; also tarnished eleetrum growths, a few eomparatively bright. At Christiana there were receut eopper growths out of fluor, foliated electrum growths out of quartz, and silver poe out of Kongsberg argentite. At Kongserg there was the most variedly interesting eolleetion of silver specimens it was possible to see, aud silver growths in nhundauce, including flat plates of silver growiug at the edges. A the British museum were n few small electrum growths, whieh ho believed were recent. He added a list of his chief ‘home growths” since May 5th, some of which he described as of a very remarkahle character. A Deez-Sea Sounder, At the recent meeting of the British Associatiou, Sir William Thompson deserihed an apparatus he had invented to make deep-sea soundings, not with a view to exploration, but for ordinary purposes of navigation while a ship was at fullspeed. A glass the, filled with air, was hermetieally sealed at tho top, hut opened at the hottom, and prepared with red prussiate of potash. It was placed into a brass tuhe, which was elosed at the bottom, hut allowed the free ingress and pressure of water from ahove. The hrass tuhe was partially filled with sulphate of tron, and wherever this iron came into eontact with the interior of the glass tube it turned into a Prussian hlue. The pressure of the water compressed the air, aud forced the sulphate of iron up the glass tuhe, according to the depth to whieh it deseended. The glass tube, partof whieh retained its original eolor, was then measured on a scale, and thus the depth of the sounding was indieated. For the purpose of being lowered into the sea, the tubes were attached to the end of a long piece of pianoforte wire, whieb weighed ahout 14 pounds per mile, and was capahle of hearing a strain of 220 pounds, At the extrenie end a 22-pound sinker was fixed. The ahsence of any friction from the wire facilitated rapidity both in sinking and hauling in, Some tuhes were exhihited which had been reeently used in taking soundings on hoard the White Star steamers Britannic and Germanic, during a voyage to New York and hack. The soundings were made when the sbips were going at full speed, at depths varying from ae 100 fathoms, and were perfeetly successhi, Tue Fiusu or Frvrrs.—It is generally supposed that tbe flcsh of the fruit provides the first food for the germinating plants of its seeds. Such, however, remarks the J/ownal of Chemistry, is not the ease, for here, as in other eases, the first nourishment is drawn from the seed alone. The flesh of the fruit hears no relation to the emhryo; it is a kind of outcast suhstance or excretion of the plant. In most of our cultivated fruit trees, too, the great mass of this flcsh is the result of cultivation. Thus, wild cherries possess so little flesh that they do not repay the trouble of plucking. Iu the mountains of Pontus grapes arc fouud so small that they are uot worth cating; and the wild apricot, and often, likewise, the wild peach, possess no flesh at all, the former, indeed, heing. like a leathery two-valved capsule. The flesh of the fruit of most of our cultivated fruit trees is analogous to the enlarged roots of the turuip and beet, and similar plants, and is simply the product of eultivatiou, which is much sooner lost again under neglected eireumstances than it was originally artitically produced, One of the most able Freueh hotauists, Professor Lecog, of Clermont Ferrand, instituted numerous experiments with various wild plants to induce then to form fleshy roots, aud he was almost invariahly successful. Just as it is the task of the agrieulturalist to increase the volume of his roots, so it should he the aim of the fruit gardener to increase the flesh of the pome, stone, herry fruits, and the substances stored up in the cotyledons of nut fruit. Praticar Ixstrection.—Tho tron Age says that auybody with whom there yet lingers a doubt whether summer schools of science may not niean pienics and n good time generally with a few scraps of learning by way of a sandwich, may bo reassured hy the actual hard work rea of certain students belouging to the School of Mines, Columhin College. The students referred to were 12 volunteers from the elass of ‘78 in tho department of eugineering, of whieh W. P. Trowbridge is Professor in charge; Henry 8. Munroe being assistant Professor, with this summer school under his immediate eare, Last mouth the 12 went to Drifton, a town in Luzerne county, Pa., and there were set at work in n coal mino—the actual work of the miners, handling o pick, drilling tho blast holes, loading the cars and the like. Among tho lighter work required of them were tho various constructions ueeded iu tho mino for supporting or lining tho openings, and similar details of ordinary mining labor, Several days were thus spent, the proprietor of tho mine, Mr. E. D. Coxe, and the regular miners in his employ, all taking a hearty interest in the scheme. Each of the studeuts was afterward requirod to furnish drawings and an essay from tho nates taken during their labors. The experiment in education is regarded as highly suecessful. AmeRicaN Pianrs ABroap.—M. Boreau, in a paper read hefore n Freneh scientitic sueicty, yives some curious instances of tho rapid distribution of certain foreign plants through the medium of water. The Panicum diyitarin, an American grass, first diseovered near Bordeaux in 1824, has spread widely in tho neighhoring departments, and has got as far south as Tounlouse. Anvther grass from southern elimes, the Stenotaphrum Americanum, is spreading its powerful roots in the sands at the mouth of the Adour. The Anacharis Canadenis has invaded the lakes and rivers of Euglaud, Scotland, Belgium, Holland and Germany. In Belgium aud elsewhere drains have heen rendered usele s, and eanals have been completely obstructed by these plants; and in many large sheets of water it suffers no vegetable life hut its own to exist. Since 1871 this formidable strangor has been gaining a foothold in Frauce; it has heen found on the outskirts of Brest, and it swarms in the waters of the Paris parks, Auother plaut of the same family, the Stratiotes aloides, intro. duced in 1828 in the neighborhood of Mans, has followed the course of the river Sarthe, and abounds in the neighboring lakes. Fiurp Carsonre Acrp in Rocxs.—The eommittee appointed by tho British Association “for investiug the conditions under which Jiquid carbonic exists in rocks aud minerals,” recently reported that, according to the method of determining the exact temperature at which earbonic acid in the eavities of rocks and miuerals beeame gaseous, the temperature known as the ‘‘critieal point,” at whieh Huid carbonie acid was found, was 39.92° Centigrade. The acid was found to be eontained in minute eavities of the rocks and minerals, and experiments had heen tried-upon sapphires, garncts, and other precious stones, aud the result had heen the discovery in these of earbonic acid. A curious fact had also been ascertained—i, e., that certain’ bubbles in the fluid cavities approached heat, whilst others reeeded from it, The ehanges of the earhouic acid from gas to liquid and from liquid to gas were found to be produeed hy the hightening and lowering of the temperature; atl in some of the cavities neither the gaseous or liquid form of the acid was to be found, the cavities being filled simply with water. Mr. Rusktn’s Capiner.—The minerals and precions stones in the museum at Walkley now form a collection of marvelous heauty, aud aro almost as varied as they are numerous. They are being arranged hy Mr. Ruskin in 20 groups namely, silica, oxide of titanium, oxide of iron, alumina, potassa, soda, magnesia, caleium, glueiua, flourine, carhon, sulphur, phosphorus, tellurium, urauium, tin, lead, copper, silver and gold. The founder of the institution, in his “Deucalion,” informs us that ‘‘the mineralogieal collection is fully descrihed and explained in the catalogue, so that auy young people may begin their study of it without diffieulty, and so chosen and arranged as to he eomprehensihle by persons who have not time to make themselves masters of the science of chemistry, but who may desire some aceurate acquaintance with the aspeets of the principal minerals which compose the world;” also, that ‘‘every one of the specimens is chosen for some specialty of character, and the points eharactcristic of it ure descrihed in the catalogue.” CHLOROPHYLL, or the coloring matter of plants, has been found by M. Fremy (as our readers may kuow) to eonsist of two principal eonstituents: one yellow, and ealled by lin phylloxanthin, and tho other a dark hluish-green, whicb he ealls phyllocyanic acid. Having furtber inquired into the manner in which tbe substances oceur in the orgauie tissue, he concludes that “the eoloring matter of leaves is a mixture of phyloxanthin and phylloeyauate of potash. Tue electrical illumination of the Lyons railway station it being completed. They are now usiug twelve electric lamps. This number will be enlarged successively to twenty-four lamps, fed with one light-producing and one light-distrihuting machiue. It is helieved that twenty-two horse power will give a power of 2,400 gas-lamps, usmg 100 liters each per hour.