2 3 6 Notes and Comments. !j. F. I.,

Notes and Comments.

TESTS OF N E R N S T LAMPS FOR PUBLIC L I G H T I N G .

At a recent mee t ing of the Brit ish Ins t i tu t ion of Electr ical Engineers in London the results of the exper iments with the Nerns t electric l ight for public l ight ing purposes were given. A mile of a street in Hackney, one of the London suburbs, has been l ighted by means of these lamps to obtain conclu- sive data regarding the i r durabil i ty, efficiency and suitabil i ty for such work. The main difficulty experienced was in connect ion with the s tar t ing of the light. This, however, was overcome by means of the au tomat iehea ter , which is put out of action direct ly the lamp l ights up. But the result of this attach- men t was not a t tended with absolute success, since considerable uncertainty exists in connect ion with the durabi l i ty of the glow~.r. Some glowers lasted only I5 hours, while others remained efficient for 1,o7o hours, bu t the average life was 305 hours. This lack of uniformity consti tutes one of the greatest objections to the wider uti l ization of the Nerns t lamp for public lighting, despite its superiori ty in many impor tan t features, and will necessitate con- siderable improvement before it is extensively adopted for i l lumining the streets, wi th tha t economy which is essential for such purposes.

STRANG E FACTS ABOUT T H E EUCALYPTUS.

Mr. D. E. Hutehins , of Cape Colony, who in I882, in conjunct ion with Sir A. Brandis, discovered the remarkable sun-power storage capacity of the eucalyptus, has again been drawing a t tent ion in Nature to this extraoadinary feature of the tree. According to Mr. Hutchins , a eueaiypt p lanta t ion in tropical mountains, such as in South Africa, under favorable circumstances, stores up about one per cent. of the solar energy received on the un i t of area and it is considered much cheaper in some parts of Cape Colony to plow up the land and plant a forest of quick-growing trees than to impor t coal.

In 1882 Mr. Hutch ins and Sir A. Brandis, as the result of the i r experi- ments , discovered tha t eucalypts p lanted on tropical mounta ins produce fuel at the rate of so tons - -d ry weight at 60 pounds per cubic foot - -per acre per year in perpetui ty. The eucalypt p lauta t ion reproduces itself when cut with. out fur ther expense, and its dry t imber, heavier t han coal, has an equal or a h igher the rmal power, bulk for bulk, than coal. This resul t was obtained as a measurement of the m ax i m um yield of Eucalyptusglobulus on the Nilgiris, Southern India. If a chance tree on a chance mounta in in a chance soil can produce the equivalent of 2o tons of coal per acre per year, i t seems not unreasonable to suppose, Mr. Huteh ins suggests, tha t by selection double this, or 4o tons, can be produced. A powerful sun, a heavy rainfall , and a very rapid forced growth are the essentials of such a product ion of wood fuel. A glance over the rainfall map of the world shows these condit ions are fulfilled over about 8,ooo,oo.%ooo acres of its surface, which is between one-fourth and one-fifth of the total land surface of 35,2oo,ooo, ooo acres. One-half of this area under forest migh t thus yield the equivalent of I6O,OOO,OOO,OOO tons of

Sept., x9o3. ] Notes and Comments. 237

coal yearly, which is more than a88 t imes the world 's present consumptiou of coal, assuming tha t coal and eucalypt t imber are of approximately equal heat- ing power. On the basis of the actual forest yield of t h e p r e s e n t day, we have half of this, or the equivalent of 80,500,000,o.0 tons. In Germany, one fourth of the total area is under forest, and tak ing the German s tandard of one-fourth forest, on the basis of the present max imum yield we should obtain 4o,25o,coo,ooo tons ; while if the max imum forest yield be converted to an average forest yield there would still remain a yearly product of 2o, x75,ooo,- ooo tons, which is r a the r more than th i r ty t imes the world's present consump- tion of coal• Thus it is seen tha t the yield of firewood from the world 's tropical and extra-tropical forests, wherever they are fully stocked and scien- tifically worked, will yield the equivalent of from 3o to 122 t imes the present consumption of coal, or even up to 243 times the present consumption, if by cultivation the present t imber yield be doubled, as it migh t be wi thout difficulty.

T H E ANCIENT RUINS OF RHODESIA.

The remarkable ruins in South Africa, which by many are boldly declared to be the remains of King Solomon's mines, are fully described and i l lustrated in a recent work by R. N. Hall and W. G. Neal. No theories are offered for the presence of the ruins in savage lands. The authors, however, seem to incline to the opinion of Prof. Keaue, which is, in brief, t ha t " the ' gold of Ophir ' came from Havi lah (Rhodesia), and was worked and b rough t thence first by the Himyr r i t e s (Sabmans and Minmans), la ter by the Phoenicians.

• . The numerous objects of Semitic worship and the f ragments of Him- yaritic script found at Zimbaye and elsewhere south of the Zambesi leave no reasonable doubt tha t the old gold-workings and associated monuments of this region are to be ascribed to the ancient Sabmaus of South Arabia and the i r Phcenician suecessors."--Scienlific American Supplement.

THE USE OF P H O S P H O R U S MATCHES P R O H I B I T E D IN GERMANY.

The Reichs tag has passed a bill forbidding the use of whi te or yellow phosphorus in ma tch-making after January I, 19o 3. The Secretary of the Interior, speaking in favor of the bill, said tha t phosphorus not only caused necrosis three or four years after a workman had left a match factory, but that the disease thus contracted was heredi ta ry , so tha t whole families were affected• So subtle were the effects tha t the bones were fractured wi thout the person at first be ing even aware of the fracture. The Government has reported favorably upon a match-manufac tu r ing process said to be safe and harmless.--Scientific American.

ALCOHOL AS F U E L FO R I N T E R N A L COMBUSTION ENGINES.

Tests made by C. W. Weiss, at the Mietz & Weiss Engine Works, New York City, with Cuban and Brazilian cheap alcohol as fuel in thei r s tandard kerosene engine, have been reported as ent i re ly satisfactory. The object was to substitute alcohol for ~erosene, the former be ing considerably cheaper and