SCIENCE NOTES.

Otago Witness, Issue 2849, 21 October 1908, Page 76

SCIENCE NOTES.

— The camera's estimated record is 100 million stars, but one astronomer, it is eaid, is to attempt an actual count, using % microscopic gauge in going over the zeveral hundred plates, each with 20,000 to. 200,000 stars. —In the report of the authorities of the British Mueeum it is stated that a lexicon \ containing, a collection of Latin 'aboriiiand | symbols has been acquired. The invention of these symbols is attributed to M. Tullius j Tiro, the freed-man, of Cicero. 'Another ; interesting acquisition is a rukd tablet^ dating from the third century a.d., which ] was used for teaching Greek grammar to 6choolboy6 in Egypt. j — Steel corporations have started to j employ' a specialist whose special , duty is to watch the colour of the flame, and his flight is so trained that at the exact moment j when the right heat has been reached he ; can throw the lever and cast the metal. • In the same business sight figures jn fixing . the quality of the steel bar, avoiding the • expense of laboratory testing. , i — The diamond was first burned by Davy ; and Faraday in 1814. It was hekl on a • • platinum rod in a glass globe of,Z2 cubic i inches of pure hydrogen, and the^lhike oi"j Tuscany's burning glass— a lens of l4im awl j one of 3in separated 3£ft — concentrated the - sun's heat. In three-quarters of an 'jaonr . the stone burst into a scarlet flame- Out j of focus Jft blazed four rninutfes, ' &nd 'wae^ consumed in two mort trials. '- ' i —On the Danish island of Sjalland a there i is an electric lighting system wmRS? is ; driven by a windmill. The wheel tis 4.6 ft"; in diameter, and is supported by aVfower, 45ft high. The area of the blades .expeeed, to the wind is 340 squaTe feet, and with' a wind blowing at the rate of 23?t' a second the mill will give 8.*6 horse-ppVer, Tihe speed is then. 24 revolutions 'a iriix^ute. Current is supplied to 378 incandescent and six arc lamps, besides -several small' inbtors. ' . — A very interestingvfaci has been' jnade ! known by Captain Musgrave concerning a 'boa-constrictor, 13£ ft in length, whim he , shot in South America. He scientifically ! dissected it, and in the body, under' TYhW' appeared to be. two distorted settles^ "li© % found two rudimentary legs, witfi joints- 1 at "hip"' and "knee." These legs were; ■but l£in to 2in long. Rudimentary : legs;' aj-e found in- -the python family, but this is " believed to be tihe 'first example of a boa- j Vonsbrictor's fags being identified. ] — For 2000 years the learned men of j Europe debated as to whether thie or -that j place was the site of ancient Troy;' or- ; urihether there ever was such a place at ail. j At' last (only 25 years. sago) a retired ! man j of business named Schliemanr ' had a ' "happy thought"— it was not'ihe thought' of, a learned pedant, but of a scientific investigator. He said, "Let us go and ; ccc." And at the exipenee of a few thousand pounds tie went and found 1 Troy and Mycenae, and revealed — " discovered" — the i [whole matter. That was the most tre : ' mendooe and picturesque- triumph of the t scientific method over mere talk , and pre- < tended historical learning which has^ever fceen seen>.since'humcun (record has existed. * —Dr Plemmipg, of the German army, : has been- studying, by means . of baHoon royages, the of microscopic bugtoismtf through the atmosphere.' ' He Finds (that the current assumption 'of -the j Absence of germs from, the upper strata. \ j%B erroneous, and that bacteria | | attain, and continue to live at, e'lev&tfcms i cf more than 13,000 ft. Nor does the''num- I Jber'of bacteria dimmish in proportion to 1 the increase in elevation, as might be ex- f peeled. On the contrary, it remains nearly ; ; constant for the-, first 1600 ft, Within 7 Una \ I limit the number ie 12.9 per litre (365'^>eF i Cubic, foot), while from 1600 ft to dfeoVe] l3,opoft it averages O.37 par litre (1G.5 P^r'j cubic foot). The number of germk~'isi sffetAed by the duration of sunshine}' feufcjj no jW&pfc "due to-*rain or snow coufd be'i -^aiteclieing that even the cheapest m&ftu- ' /ict*red .(refrigerator is often beyond tie' means 1»b poor, Dr Alfred Hess 1 has ' Tonstruiq^edt* home-made one whioh ie boih" praotkal l&ti novel. It ,is made h-<te"a] wooden b>x, two tin pails which fir fc one! in the other, and a bucket of sawdust. J ThesJarger n^il is placed inside the. box) andi-the u}t^rVenbig space " packed tightly • witkr either sa,wdu«t or newspapers. ' 'The emaller pail is- <ien placed inside the big one;* «nd a piece of ice deposited in it. Th« inner pail je then §»lf-fiUed wigh.' vfatir, and the top of the box placed 1 oV»r it. ->j& it churned that a very small piece of ibe ii> this box will keep for 24 honrs, and that fl bottle of milk in the inner pail willi- remain for that length of. time at a tempfatature of 40deg. This temperature wijkxttot permiir flf the multiplication of ib&cte&a.^ . -— Jade*, iOx& green stone, -which is said to "bring, luck, is very popular just now. The ddeavbf jade possessing tihe virtuare of in- i iiuenfoing fortune arose in Ohina, where ! the BBope is so valued that the finding of ' a pfcrt'sularly fine piece causes the Slate '. t< taike- jioseession of the land where it wast found. Tho beet specimens- repre- ' eent J all the hue 6 and effects of sea foam ; [ ibut -thefte are quickly snapped up by the f collectors, and seldom come into lie public anadiet. There is another cause for the popularity of jade. Its peculiar green tingo nas &c effect of making the human skin 8ook; very white. In this connection the quality jof the stone ia of no account, so long as the colour is there. Indeed, many of the less expensive jade ornaments are made from chips of a stone which contain noticeable flaws. . — ffey those wild are not naturalists or { an^n of" science it is an object-lesaon of the ] highest importance that the 1 speculations and observations which have led to the • igeneral acceptance of a new view as ,torj She origin of the specie* of birds, butter- ' flies, and flowers — in itself apparently a t matter of no consequence to human life and ' progvppse — should have necessarily led to a ' now epoch in philosophy and in the higher ' Statecraft ; in fact, to the establishment ' of tjSe- scientific knowledge of life as to ' *he one sure guide and determining factor ■ of civilisation. How to breed a health? , ' capable race of men, how to preserve buch •' ra**» -too™ to educate <$nd to train it w> tnateMW-best qualities of mind and body toay ,Jbe wrought to activity an<l perfection ' 4h*t 'jfT^whxb Darwinism can teach us, ainj ; grill us when the great subjectd of ' jßhe^fmbe and of variation ore more fully anvef&sted by the aid of public funds, And^jwien the fcuman^ mind has been as c«reftlly examined and its laws as well^ ••oeriained as ere those of the human". body- 1 — JI. Guillaam© remarks that bis ex-

-perimente lead to the conclusion that all tioiids under heavy pressures tend to be converted into an amorphous state, which iias no discontinuity with the liquid and gaseous phases. At the pressures met with a few miles below, the surface of the earth the - rocks or other material are at once fluid, and yet as rigid as eteel. They will flow under the slightest lack of symmetry in the forces acting on them, though their viscosity is, of course, enormous, and hene-p ! enormous lapses of time are necessary for s large movements. He suggests that tho 1 conditions met -with ,in the interior of the j globe may *uffioe to account for the produc- { tion of radie-aetive elemente by a process Jof synthesis. If the enerjnous pressure •f obtaining in the interior of the globe is i the cause of the formation" of uranium, j then the radio-activity of Jhe latter is ] merely a restitution of a small portion of ! the energy liberated on the condensation |of our globe. The fact fhat pressures of ! 2000 atmospheres have been found to 'have { no apparent influence on the radio-activitT : ,of radium does not, in his view, provide a conclusive , argumenjt t-fos • hypothesis advanced, since this pressur* ! is" small relatively to those existing in I the interior of the earth.-t-Engineeringß. j- — The first establishment in the world • •for the -manufacture of radium (says \ Popular. Science Sittings) ia located at j-Nogent-suac-ilaTne, in France. The pror ' cess tof exifcractinig radium-bromide is elow^ radecugj-ing from two to five months; tedious :j>in- ifie, ,^ast .degree, and almost incredibly ' expensive. ' It is estimated that,' counting 4nthe cpptf.of machinery and labour, botai of | tfao .c^niparatively unskilled labourer in the ', factory , and ' that of the trained chemical ; experts who 'perform the concluding operei lions, • the cost of extracting one kilogram of pure radium -bromide (about two and a-■--fifth pounds) would be £16,000,000. No .-Buch quantity of radium has been extracted' from, its ores, and tho most that any -scientist can hope to procure is a few .small particles, hermetically sealed in a .'glass tube, and these bits — most of them i one-half to ono|tenrth the sise of a. pin ; head — are the material with which chemists and physicians make their experiments. ;/The. r x-a4ium factory, or, more properly, ,' .radium-bromide factory, is but an- ordinary 'building* but* within it is carried cm> the ?. -process of abstracting from many tons of , mineral the" microscopic particles worth of times their weight in gold. a The materials ..arg varied, principally ( being' pitchblende," irom which uranium is obtained, espec,ially valuable 'as a pigment 4or glass, to which it imparts an\ exquisite . greetaish-3-ellow" colour. Pitchblende is of j .itself a yery .remarkable compound, coni taming' the sulphates of almost all known { minerals. By waggon loads the material I is seat through a crusher, then subjected, r,in a -greaf; tank, whose _ contents »re. stirred by '-a mechanical 'device, -fro processes., co ! bumef pus - and scientific that to give even ! s crude notion of them would require a ! volume. , After continuing the separation •'-and purification for monihs, there remains ,-at the bottom of the great taut a .handful of impure radium-bromide, which is turned j over to <ihemists of long experience for I final reduction. When they nave finished their work there^ are left A few grains of •the substance known as radium-bromide; i-Ob is., said by..,Pjrole^sbr W. >J. Hammer if that there wre o^ily two particles of perfectly radium-bromide in the world. One .is in the factory, arid fee is the owner .of "the, otiher. This experimenter will, howt «ver, shortly place on the market a comj paratively-pure radium salt wihich will be I isold ,at • the' low iprice of approximately ' £545,000 per lb. Opinions differ as to what i has been or will be accomplished by radiam. i The most singular property of this" magical J.elemetni if^the faot^jbnat it gives out heat ' ' 'constaiMyV^stmost uniformly and under all ' without loss of weight, /ichange o| "-'substance -or detvariorartion. A f particle radium 3ias been known to i'Trad-jajfe' its jheat for a" year •or two at a J'jffime, a^d wihen weighed again has not 'lost >a t*6n'-fihouaaa>d£h pert of an ounce. Every 1 icme'thipws the various ways in which heat >i« produced, but radium is a self -producer oi hea±, and 'so -far as we now can see, the .;^rooesa .may continue indefinitely, and it f- is tihis ] property which makes the little } grain^ o* radium-bromide, which looks I exactly,, .like a grain of common salt, so woncksrtul ip the ,eyes of the chemists, for lit apparently oontradicts flatiy every ! principle regarding the evolution of heat.