SCIENCE NOTES.

Otago Witness, Issue 2803, 4 December 1907, Page 76

SCIENCE NOTES.

—An irrigating canal has just been completed in Hawaii. It will carry 45,000.000 gallons of water "daily through 16 miles of tunnel 'andL opfcn "'d/teh, It^s purpose, is •primarily -carry water, for * irrigation from 'We" Waimea' River to. £he Kekaha plantation, but' on "its" way *it will be used at two- -places- for the development of electricity. *•' "' ' : ; . —Dr A. \ Graham Bell has* srected, on hie- Estate at Benin 'Br^agh, N.S. lt> A tpsrer '80ft -buffi" of the bells wfrichr'he invented to. secure .great strength and lightness m the construction of kites. The engineer was Mr F. W. Baldwin,, of Toronto-, who stated" at the qpening ;eremony that the. tower weighs les3 than five ions, and will carry a weight of 5Q,0001b. — A new method of cutting steel ;s; s said to have been patented, by a Belgian., engineer. The process consists in first heating s the ■aietah'by hieans" of ' 6xy-hy<3rogen flame and then cutting ft by a small ctream" of oxygen, gas, which" un^tej ,w,ith . J;he 3t'eel and form* a fusible oxide, which flows freely from the out. It is said that the cut is fully as smooth as that made by 'the 3aw, and is _only l-100in »fde. # -"'The cinders" from the waste burned In some European municipal destroying plants are made into building materiat by crushing, mixing with' cjsmenf." and moulding into great wall^ slabs. These have door and window openings, and even an interior iron framework for holding them in place, and 1 some weigh as* much as 11 tons. The frames are bolted together, the joints being closed with cement. — The, mean height of all the !and now above the sea is referred to by I/yell as being 1000 ft. The mean depth of ;he ocean is at least 12,000ft — that is. it exceeds th«> height of the land 12 times. This is because the extreme heights of the land, although probably no less than the extreme depths of the sea. yet are exceptional heights, whilst the ocean maintains its depth over enormous areas. Owing, however, to the fact that the surface of the ocean to that of the land is as two and a-half to one, the. ocean would accommodate the whole of the land 30 times over, were it all pitched into the ocean areas. — Ozone, which is an allotropio form of oxygen, has long been recognised as an active purifying agent in the atmosphere owing to its powerful oxidising qualities, ' but the question of its origin has teen much disputed. The investigations of Monsieur Henriet, in France, have led him to the conclusion that ozone forrrrs mi the upper regions of the air. probably under the influence of the ultra-violet, radiations from the sun- and that it is brought down towards the surface of the earth both by descending air-currents and by drops of rain. After a shower ojf. rain the quantity of ozone in the air is always found to have been increased. . — The presence t of radium in unexpected Quantities ,- in th« ' rocks qf j the Simplon runnel borings leads Professor Joly to suggest that this element, may be a factor in mountain-building. In! the course of ages, he points out, ' radium and its parent elements thorium and uranium would be transferred in the processes of denudation from one area to another. And this trans-'* ference would mean the sh if tine of areas * of high temperature, which might eventually result in crust movements. In this way a factor in mountain-building — viz.. the heat resulting from- the presence of radium, would be. transferred from point to point of the earth's surface. —So important is an exact knowledge of the atomic weiehts of the various chemical elements, that there is an international commission which undertakes to revise 'fhe list of such weights once each year, in accordance wirh *he latest researches. The list for 1907 contained 79 ; elements. Among these there are seven whose atoms are heavier than those of gold— namely, mercury, thallium, lead, bismuth, radium, thorium, and uranium, which has -the greatest atomic weight known. The weight of an atom of hydrogen, Btill the lightest of all known substances, is fixed at 1.008: that of an atom of oxviren at 16: that of an *tom of gold at- 197.2: fliat of an atom of radium at 225: and that of an atom of uranium at 238.5. —The known number of asteroids or minor nlaoetg had by 1906 reached 603, end still the discovery of these miniature worlds continues, especially with the aid ; afforded by celestial photography. Among [ a rast multitude of stars crowding a photosranhic plate one. nerhans. will be -seen ' ra hs.nr^ Jhiwti a. aliort +!iira line on ili» \ plate •during its hours of continuous ex- ' posu-o The astronomer knows at once j rhst n is either an asteroid or a oom«>t. Subsequent observations scon decide the poinr. Only the more interesting ones are afterwards observed with attention : but, once discovered, they cannot be ignored, and fhp rapid growth of the flock becomes an embarrassment. Eros, which at times approaches the earth nearer than any other regrnlat member of the solar system cxeent the moon, and Asteroid. No. 588. which at apVelion is more distant that JuDiter. remain, a. c far as th^ir orbits are concerned, ihp most interesting members of the entire jrrot'p, and are kept under constant observation whenever circumetonces permit. — Some very intfrc^'ng experiments as to th<» effect of the Rontgen rays neon butterflies at various stages of th J ir evolution have reoentlv been niadf by Dr Hasebrook, of Hamburg. The pu^je of several moths, including one of the hawk-moth which had passed over the winter months (September to May), were not affected at a'l. despite repeated intense exposure to thp rays, and thp Lepidoptera emerged in due course under perfectly normal conditions. The caterpillars, after casting their skine for the last time, were not affected by the rays, except that they remained a little smaller in size ; the fornvation of the pupas was not interfered with in any wav, nor was any dffference caused in the duration of the comatose or quiescent stage. On the contrary, the exnosture to the rays during the last caterpillar and first pupa stages caused marked alterations in the Lepidcptera, the moths of several varieties being smaller, and showrrifr marked degeneration in the formation of the scales and down on the wings and increase in the black pigment. although the characteristic markings were maintained. ' ' Another ' peculiar phenomenon was that ihe moths had entirely lost the power of flight. It is hoped that further experiments may be' mad« in this direction, arid that still more interesting resnlta may be obtained. -In -riew of * possible substitute for

radium, tne Scientibe American says: — An interesting announcement of which we shall look for confirmation with interest comes from the School of Medicine at Hochefort (France) regarding & new radioactive substance, discovered by a young student named Luncien. It. is eai<j the substance is uranyl-Molybdate, and as ilb constituents.' tiranium and molybdenum. v.re fairly "abundant elements there "should b© no" undue* trouble- In providing tne materials, nor • would « there be in 'preparing the substances The roolybdate is formed pj ?ddin& ammonijim^inoiybdate to-uranyl Wtta,^when g , «hij>e .a^iorphous powder ■jeparatee. Thif a dried- -in tne< c^rk, and apparently must be kept there, as it ife Unstable. It is 'laid to .give radio-active effects ttraciiijally as intense as those given by radjtsro.- Though costly — about HOdol an ounce — the uriee is slight compared to radium, which has reached many thousands of dollars an. ounce. - • '- -- The U9e >fi«teara,hirbmea for driving eleotric- senerators propelling large ship*. J.'ke the Dreadnought. Carmania, and Lusitania, has created jmuch interest. The ' Gfreefc philosopher Hero describes a primitive turbine' in the second century, 8.c., and though the machine was- little better than' a toy it worked fairly well, and may • be regarded as the earliest ' tise of steam for +he production of- ■motion. De Laval constructed a turbine in 1882 for the direct drivinjr of milk separators, while Parsons brought out his first turbine in 1884, which he employed for driving a amaJl electric generator. A turbine is a, machine in which a rotary motion is obtained by ihe gradual change of the momentum contained in the fluids. The fluids commonly used for the purpose are water and steam. The steam turbine belongs to the same "glass of contrivance as the hydraulic , turbine or' water-wheel, and it is constructed on the same principles. What , may be called the new history of the turbine began in 1884, when the Hon. Mr Parsons took out his first patents relating to steam turbines, and in 1885 produced a turbine which made IP.OOO revolutions a minute. Since then Mr Parsons has made many improvement;, and there is seen to be a great future in store for his invention. —On looking at the moon through a telescope we sco that its ordinary aspect has changed, and that the shadow of o, vague human countenance,, with which popular imagination has for centuries been familiar, has disappeared. The eyes and the mouth have become immense plains; the cheeks «nd the chin bristle with mountains, and we find ourselves confronted by an earth in the sky. Some of the vast cavities which we see are several miles in depth, and from 60 to 120 miles in width. Colossal Alps and giant Apennines, which iise to the heiprht of between three and four miles, break upon our sight; deep, hollow, abrupt ramparts, angular ridges, valleys, dells, and numberless crevassesall, and' a thousand topographical details, ar& brought plainly to view" ito the vast field of the telescope. ' As an instrument which enlarges • an- image- gives to us the same rewlt as >ye should get by our near approach to it, we see by its aid, as plainly as though we. were *t each place, the contour? .And the general formations of the " Sea of the Crisis," of the " Set. of Serenity," and of the " Ocean of tiie Tempests" — all those formations, those great grey spots, the nature of which is still shrouded in mystery, and to which we have given the name of "seas," naming them thus when we had no suspicion <if their state of dryness, when we believed we saw in -them miniatures of -thoEe in our own globe. The theory of these formations having been seae has been of late year 3 entirely abandoned. — From an article entitled "About the Moon," by the great French authority, Camille Flammarion.