SCIENCE NOTES.

Otago Witness, Issue 2815, 26 February 1908, Page 76

SCIENCE NOTES.

— The rings of Saturn are thin plane ■heets, most probably less than 100 miles in thickness, though 168,000 miles in diameter. They do not, however, form on unbroken sheet, but are composed of three divisions— «.n outer one, about 10,000 milea wide, separated from the second by a dark space of 1600 miles; a second, about 16,000 miles in width, brighter tiban the first; and this shades gradually into the third, which is faint and partly transparent; doubtless because the particles which compose it are so far apart that we can see through between them. — The St. Petersburg correspondent of the Daily Telegraph states that the public declaration fthat radium effectually cures poncer is well worth "recording. The vouchers are Major-general Poehl and several physicians. Genex&l I*oclxl suif-ered from cancel on the ijp, naar the nose, and al- , though an immediate operation was deemed imperative, the paiaent preferred to have J recourse to radium', obtaining a maTke< improvement a£ter one week. Then followed a full month's rest, and 1 five further applications, the result being a complete cure. > — "Marine seiches," or "vibrations of the sea," are pulsations usually having periods of 15 to 20 minutes,- though varying in different localities, and they occur on ooaata in addftion to the waves of short duration due to wind and those caus<"*l by the regular ebb and flow of the tide. They have brought out various theories. A recent study has been made by Professor Giovanni Pla>tania at C^tapia, .Sicily, and he concludes that the principal cause is air waves or variations of atmospheric pressure. — MaMeahfe oast iron consists almost entirely of ferrite and temper carbon. It has a tensile strength of from 40,0001 ib to 60,OC01'b per square inch, with am elongation of from 2£ to 5 per cent., which in special cases may go as high as 8 per cent., and a reduction of area of 2^ to 8 per cent., and may go as high as 12 per cent. A lin bar on supports 12in apart should bear a load at the centre of at least 35001b, and be deflected at least £in before breaking. Thin sections should be capable- of being flattened out under a hammer and bent double without cracking. — Bradley Stroughton, in School of Mines Quarterly. — A paper on th« predetermination of train resistance was read by Mr C. A.. Carus-Wilaon before the Institution of Civil Engineers. Among the practical conclusions arrived at are that die resistance of the air, with a train of bogie-coaahea, running at 60 miles per hour, amounts to about one-ho4f the total tr*c*ive effort required to haul the train. Experiments conducted by the Si. Louis Electric Railway Test Commission show that a large reduction can be made in the front and rear sir-resistance by shaping the ends, "and that Jby this means ' a saving oan be effected of 10 per cent, of the total tractive effort with a long passenger train, and 30 per cent, with a single coach. — That explosives sometimes produce curious effects on metals ie a well-known fiaot, but it is seldom that a/ hole is blown in thb centre of a piece of steel. To test the destructive properties of the explosive known as hathomite, an ounce of it was pUwoed on « steel plate about an inoh in .thickness, the plate in turn resting upon a cylindrical piece of iron bored through the centre. After tfie explosion it was found that the hathamite had oust a piece out of die centre of the plate the exact size of the hole beneatih, indicating that the force of the explosion had been directly downward. In another test « steel conical shell WAS filled with the -substance and exploded, the shell being blown into fragments. *^Dr Radard, a Geneva dentist, after having for several years made experiments .wiith the narcotic effect of blue rays of light, - has just submitted his reeuite to the Swiss Society of Odoni©*ogy. In the •report he claims tihat a. complete narcosis (atSipefying effect) can be obtained if the <raye of a blue electric light are brought to t>ear on the human eye, while all other *ay* of light, particularly of daylight, are kepi off it. The narcosis thus ofobajned is SO complete tfonit, during the same, little dental operations, saoh as pulling or filling teeth, etc., otn be executed without ca.u&iag the parent the least amount of pain. While the effect oi the blue rays is a very Mtrojo^ one, that of violet-blue and green r*ya v leas intensive, and yellow or red rays show ao effect at all. The inventor is -unable ho give a definition of the cause of fchii remarkable discovery. — Meteor trains are the luminous cloudlike forms scan after the flight of a meteor, whidb usually persists some time after the incaradeßcent nucleus has disappeared. Professor C. O. Twwbridge has collected most of the evidence given by post observers, and <$ioOU6ses the data with the object of Jdodutfting information concerning the physical Constitution of tire upper atmosphere. It is Sound 1 that meteor trains seldom, if ever, occur ni attitudes below 45 miles or ovor 65, tihe usual height being 50.60 miles. In thi« «xne {iiere appear to persist certain conditions favourable to the production oi meteor trains. ' AJs we know that ttte mobt important condition of a gas respecting the production of electric disc&cvrges is ltd pressure, it seema possible thai the Buirt*bie degree of rarity is present at the above-mentioned altitude. As many of the observed trains were visible for 10 to 20 mdinites, the' phenomenon may be regarded as a gas luminescence-; and this view is by the three facts— (l) 'the rapid lateral diffusion, amounting to as much as 100 metres per minute; (2) the great volume contained witihin the bountWy of tihe train, usually several cubic miles; (3) the observed spectrum, consisting of a few bright lines. Moreover, the •rate of decay of the glow appears to be Dearly the came as- is found in laboratory experiments, especially in the case of the eleatrodeless ring discharge. — Knowledge. — The flesh of most sea fishes and other marine anknailfl becomes' more or less luminous within & day o$ tvo after death. The light is emitted, however, not by the flesh itself, hut by certjain , bacteria, which can be oollecfced from its surface, and whidh are at common occurrence in sea water. A •hnflar appearance, due also to tie presence of luminous bacteria, ie often prevented by meat. These bacteria are harmless to human beinge, as they cannot live *t a temperature above 76deg P., and the temperaibure of the human body is 98deg IT., but living cold J blooded animals can be Jnoeujateif with lurmnous bacteria, with eurpnsing reeui-te. The Russian phyeioloe -ssfc Ta-rchanoff inoculated froge with lvKunous bacteria obtained from the Baltic.

The bacteria multiplied in the blood, am caused the entire body of the frog to cmi ■light. The luminescence, which wa especially intense in the tongue and othe , sort _ parts, continued three or four dayi ' ; Similar phenomena, have been observed i> occur na.tura_y in cold-Wooded animals. 1 few years ago tihe French naturalist Gian found among the sand-hoppers tha Bwermed on the beach at Wimereux om winch, instead of hopping, crawled slowl; over the 6sund and glowed brightly. Qi examination, the body of the little orusita cean was found to be filled withvluminou bacteria. When other sand^oppers wei> inoculated with its blood they also beoanii luminous, gradually lost strength, and soon dried, biifc oodtinued to glow for sever* hours after death. — There is a. class of sensitive plant which retract their leaflets as we approach .them as if they resented any o-tfempifc a closer intimacy, while another class, com pr-isttig all iboso vjn-es -whioh develop clixut injt organs called tendrils, will reach ou towards us if we place our hands in con tact with them, and> will even use a fingei as a support to climb upon. We know {sayj Mr J. Howard J. Shannon, in Harper*! Magazine) that these tendrils will wine just as readily about a twiig or a g*a»i stem, but as one feels tlfaese sensitive strands multiply their encircling coils abowi one's fingers, there almtfet seems to bt established between us o-nd the vegetable world a more inbimafte relationship thar has ever existed before. It is only aftel we have seen them at work, testing wit! their sensitive tips the objects they come in contact with, apparently considering their suitability as a support and then ac ceflfting or rejecting them, as the case maj be, that we realise how justly they have been called the "brains" of plant life." Th« thoroughness with which wandering tips oi plants explore their surroundings is illustrated; by an instance Mr Shannon observed in a grape vine tendril. A cherry branch, whose leaves had been variously punctured and scaJlopedi by insects, hung near the tendril, and a particular leaf had ju»t one small hole in its blade, not over three-six-teenths of an inch in diameter. So careful had been the exploration of *he leaf's surface that this one small hole had been discovered by the tendril, which hod thrust itself nearly three inches through the openinsr. The raipidaty of motion is also suiprising, particularly if the tip is stroked a few times to arouse its latent powers. X tendril of tihe star cucumlber so treated began to curl afcout hlis fingers in 10 seconds, and in one minute a complete revolution had been made. This ie much more rapid than its movements unhastened by frfetflion, for a pencil so hung as to come lightly in contact with such a tendril was not encircled until nine minultes had etoupsed. — The reludhaace evinoed by .the Britaflh fanner to adopt new machinery and methods leads us to Ishe conclusion. tih«b agriculture will be one of the laatt industries to call in the aid of electrical appliances; it is difficult to see how any saving can be effected by generating electric current and distributing it to motors in outlying positions. When, however, the mains from some large electric power company pass wkhan reach pf a form or estate tihe conditions are much more favourable, and 1 thris state o"f things must already exist in a measure .which will be largely ewtended in fiature. A recent number of Electrical Engineering: contains an interesting account of the appHoaction of gleotrioity to a group of forms in Saxony. Current is brought (rocr< an adjacent town by overhead wires carriod upon wooden poles. • Twer receiving stflitions are arran>ged, from which the f«lectricitv ie distributed to the ferm-butvld-in«* and to convenient poEiMons in £he fields for tl» purpose of driving threshing and other machinery. Sixteen fixed electric motors are- installed for chaff and retort eurtting oat erruahing, pumping, and for operating miaohinery used in the manufacture of potato spirit. In addition to this power equipment, six portable motors are provided, which may be ueed for driving pumps, circular saws, threshing mwcianeary. etc., at any point where their services are required. The houses and buildings on the farms are aM lit by electrioity, nine are lorope and about 1000 jrlow-un-ps being tssed for this purpose. This example, can only "be compered to a large estete or srroup of farms in this counSbry, and it is doubtful if such a. scheme could be a cooinieroiai success for the operating of farming machinery pure and simple. It would apoear that wood-sawing, pumping, a.nd other operations requiring power mu*tt be included' if the results are to compare fetvourobly wifih those at present obtained by the use of oil or steam engines.— Home paper.