SCIENCE NOTES.

Otago Witness, Issue 2666, 19 April 1905, Page 72

SCIENCE NOTES.

• — The discovery of radium in the solar ]photosphere has been announced by Proifessor Snyder, of the Philadelphia Observatory. His subtle research (remarks the "^Manchester Guardian) is of special interest as confirming speculations about the possible eource of th© sun's energy. If the sun contains large stores of radium, they may grttvely jnodify estimates of the earth's chronology. These estimates are- based on tthe assumption that the sun's heat has been kept up by dynamical machinery which we can understand and measure. -But now we. ihave to talce into account the inter-atomio

stores of energy which radium taps. Mr <W. E. Wilson has calculated that something 4ike 43 grains of radium to every cubic yard »f the sun's photosphere would supply the entire output of eolar energy , until the 3radium was exhausted. Thus it is clear that juntil we know more about the radium, in. %he sun we cannot speak with any confidence! tof the length _of time during which it has been .shining on us or will continue to keep His alive. ■^-Jupiter's four moons are familiar to •most persons, for they can be detected with a very low magnifying power. Some persons, . indeed, have claimed to see them ,with the naked eye. They were first discovered by Galileo just three centuries ago, *by aid of the very imperfect optical means fet his disposal, and were named respectively •10, Europa, Ganymede, and Callisto, but they are now generally known by the numifoers 1 to 4. In September, 1892. the great refracting tekscope of the Lick Observatory at Mount Hamilton, in California, with its yard-diameter object-glass, enabled Professor •Barnard to discover a fifth satellite belonging to the giant planet; and now the first - notable- astronomical discovery of the year 1905 is found in the • detection cf a sixth satellite. The discovery was made< by ProSessor Tefrine at the Lick Observatory, with a' reflecting -telescope of -3ft aperture, which originally came from England. The new satellite is said to be of the fourteenth magnitude, and is some five or six million miles distant from its primary. — The incandescent mantle has saved the gas industry ; "^ and not only saved it, but E laced it in such a position that gas lighting y modern methods of high-pressure incandescence, inverted burners, and so forth, threatens to outstrip electricity for general lighting purposes. This is no exaggeration -when, we reflect that invariably the finest etre&ts in the .great cities of Europe are now lighted with incandescent gas burners, and if the high-pressure iflcagaescent lamps ■be compared with th© electric aro lights at some of the busy street crossings, in London .-there can o& no question of the great superiority of the incandescent gasaystem. •In" fact, in several places the electric aro flights may as well not be in use in the face of the brilliant penetrating light of- the incandescent mantle. At a recent gas exhibition held in 'the Exhibition Buildings at Baii's Court may have been seen mcandes- - cent 'gas burner-, workiu© under pressure \srith tie light of which the electric arc light ■cannot compete for brilliancy,_ steadiness, -penetrating nower, or tone. Nor is it on the large scale alone that gas is seriously rivalling electricity. The inverted incandescent gas burner is hardly distinguishable in appearance from the incandescent electric Oight in the artistic lighting of domestic

ffooms. — The Hospital (February 11):— "Physiologists, and physicians as physiologists, are bound to recognise that emotion is a force outlet in action, capable of Jbeing guided by those who have been trained to bring it into subjection, but X«ert&in, when suffered to accumulate, to overpcweT persons of feeble will, and to Eompel them into courses which sound judgment would often be unable to approve. /^Abandonment to religious feeling, like / abandonment to any other feeling, is merely a surrender of the will to the emotions, and its principal effect is to render emotion, land not will, the predominant factor in the ■organism. We may, if we please, call the •religious emotion a ' good ' one, and we may perhaps recognise its feeblest form in the case of those ladies who say that they always feel \good ' in a cathedral. Subrhied light and magnificent architecture and devotional music appeal to their feeldngs in some transient fashion; but they teturn to ordinary worldliness 4 as they step out into the air. The ' cases' of the revivalist differ from these in the greater force of the original emotion, and in the extent to which it is maintained by surrounding ciroumstances and restrained from immediate escape in action. The subjects of it do Snot step out into the air ; and the force ,-which has been excited obtains no immediate channel of operation, but is restrained ■until it produces an explosion. The immediate effects of the explosion may be various ; the ultimate effect is always the same^ The subject has been taught to brood over mere Seeling until it masters the will, and thus at fei-st weakens, and ultimately annihilates, the k>ower of -self-control. The religious emoSion may appear to some people to be good and laudable, but it is in its nature transient, and the supremacy which it has ob,'tained only paves the way for the supremacy of any other emotion by which it may be succeeded " — Electricity has been put to still another new and invaluable use by the invention of ■the electrical language for the deaf and dumb. Owing to an ingeniously-contrived talking machine, which a Pennsylvanian inventor has just perfected, all mutes the .world over may some day dispense with the sign language, and may communicate .with electric finger-boards. The persons conversing- can convey emphasis in raisingor lowering the voice, just as by the strength ©f tbe inaDulsaa iransnxi tied, and ifc is said

that mutes can send their impulses of thought as readily as the operator would telegraph a message. Conversation may be carried on at a great distance from eaoh other. And by carrying the machine m the pooket mutes can communicate with each other no matter where they are— out of doors or travelling by boat or tram. The Morse code is now in use in every part of the world where telegraphy is known, and it is used in the mute system. Two persons may thus talk together as rapidly as a message can be sent by telegraph anywhere ; and, as there is no sound, the conversation carried on is absolutely private. — The moon has never been, seen with any telescope, Professor Pickering tells us in his new book, issued by Mr John Murray, which has a valuable lunar atlas,, better than it would be seen with the naked eye at a distance of about 800 miles. This ia with a 15in telescope and t perfect seeing. Tbe bigger telescopes which the world possesses are, for various sufficient reasons, not nJ ace d where the seeing is perfect. If they were moved to a tropical climate they might, under the best conditions, bring the moon within an apparent distance of 300 miles. With perfect seeing the 15m telescope would show an absolutely black object on the moon that measured only 600 ft in diameter. If the seeing were such that we usually have in the Northern United States and Europe, it might have to be half a mile in diameter. If it were not black, it would -have to be still larger. Under perfect seeing a black object a mile long would be seen if it were only 100 ft in breadth. The moon's day is 15 times as long as our own. Our knowledge of the surface of our satellite is now so complete that, while we do not know any portion of it as well as wo do large tracts m Europe and th© United States, yet at the same time there is no portion of its surface that is readily visible that is not known far better than large areas of the readily accessible surface of our own globe. — Electricity, long acknowledged to be the most important factor in modern manufacture, is being almost daily adapted to new uses, and in most cases revolutionises the various processes of previous manufacture. Especially is this the case in the recent adaptation of electric welding to the making of chain, doing away entirely with methods thought to be the most modern . and labour-saving ; introducing a process that cheapens the cost of production, and raises the quality of the product. To a native 6i France, Eugene Francois Giraud, belongs the honour of first adapting for ocftnmercial use in the manufacture of chain, the principles underlying the science of welding by the electric current. Used in connection with M. Giraud's electric welding machine is his machine _ for forming I links, an ingenious and complicated device, I into which the wire rod is fed and auto 1 matically out and formed into links. As 1 each link is being formed, it is hooked through the link previously formed, so that the links emerge from the chain-making machine cut, formed, and linked together ready to weld. An important feature of this machine is that the links made thereby are absolutely uniform in dimension and free from twist, and, as the process of welding Hoes not in any way alter the shape of the link, the result is a chain with every link exactly alike, increasing its commercial .value. The links thus formed are "fed from '-the chain-making machine directly into the electric welder, where every other link is welded on the first pass through the welder, and the alternate links on the second and last pass. This is necessitated by the fact that the links present themselves alternately in horizontal and vertical positions, and the welding machine can weld j the horizontal links only. The links are so formed in the chain-making * macKine that ifae hwo encts of the link to b© welded are on the eide of the link, with a. space of probably not over one-sixteenth of an inch between the ends, which are cut at right angles with the length of the rod in such a manner that they can be " butted" together to be • welded. As each link reaches the proper position it is firmly 1 seized by jaws, and the ends of the link Ito be welded brought tightly together. At 1 the same time, two dies are operated so as , to close on the link at the point where it listo be welded ; and the moment these two , dies touch, the link the connection is made, bringing the parts of the link between the dies immediately to the welding heat. By means of the pressure and the heat the ] link is thus welded in such a manner that the welded portion of the link is as perfect as the rest of the link, with the exception of a slight ridge formed by the pressure. J As soon as welded the link is carried auto1 maticallv forward to a point where, by blows of a die, the ridge is reduced to the size of the balance of the link. As this latter operation is taking place the succeeding link is being welded, and so on indefinitely. There are numerous features about this process of chain manufacture which tend to make it of extreme com- ! mereial value. The absolute certainty of the weld and the fact that there is no ' waste heat are important items. Skilled I and high-priced labour will be done away i with to a great extent, the cost of manu- ' factnre greatly reduced, and the daily oroduction increased, one welding machine turning out about 18,000 links of 5-16-inch ohaiiLs.per day, equal to about 20001b in wei*prt. The current required for operating one machine is not more than 24- watts per square millimetre of double section of ' material used. A great of time and money has been spent In experimenting in order to make chain without welding, but to no practical avail ; but here we have a process that guarantees a perfect weld, perfect links, and enormous production at_ a cost whioh is less than the most inferior to-day can be made under. — Dublin Penny Journal,