Aprii 8, 1897 | 
NATURE 
541 
Tue Cairo correspondent of the Zénzes reports that Prof. 
Forbes, the electrician, who has just returned from Wady Halfa, 
expresses a highly favourable opinion about utilising the power 
of the cataracts for generating electricity, and considers the 
general circumstances of Egypt exceptionally well adapted for 
its use as motive power. He thinks that the cataract power 
would be available all the year round for working the railway, 
cotton ginning mills, sugar factories, irrigation machines, Xc., 
also that it could be supplied over distances of several hundred 
miles at a cost much below that of coal. Prof. Forbes is now 
on his way to England. He will return to Egypt in September 
next, to make a complete survey and present the Government 
with a project for utilising the electricity to be generated at the 
Nile cataracts. 
Tue rapidity with which Réntgen photographs can now be 
taken was exemplified by a series of pictures recently shown by 
Dr. John Macintyre at the Glasgow Philosophical Society. Dr. 
Macintyre passed through a kinematograph a film thirty-five feet 
long, having upon it radiographs of a limb of a frog, and he was 
thus able to show distinctly to a large audience the movements 
of the bones in the limb. To obtain the photographs the 
kinematograph was covered with lead, in which there was the 
usual aperture. This aperture was covered with black paper. The 
tube was then put in the best condition, the mercury interrupter 
being used with a to-inch spark coil. 
limb of the frog were controlled by a mechanical arrangement. 
A SHORT time ago, one of our correspondents (‘‘S. J. R.,” 
NATURE, vol. liv. p. 621) described the injurious effects of the 
X-rays on his hands. He is not the only one, however, that has 
suffered in this way: several other operators, who have been experi- 
menting with these rays for any length of time, have had either to 
bear the consequences, or give up for a short time this line of 
work. An interesting summary and discussion of many of the 
well-recorded cases of dermatitis due to the X-rays, forms an 
article in the Azzdletin of the Johns Hopkins Hospital. The 
writer, Mr. T. C. Gilchrist, after reviewing the several cases, 
finds that the X-rays are even more powerful than have been 
generally thought, and hat the deleterious effects may in some 
cases be quite serious; the cutaneous manifestations are not, 
however, the most severe of the lesions, but they are surpassed 
in severity by those of the deeper tissues, and particularly of 
periosteum and bones. The discovery of this deeper and more 
profound effect calls for a new explanation to account for the 
cutaneous lesions. It seems probable that, according to the 
writer, these injurious effects may be due to the platinum 
particles piercing the bulb, and then attacking’ the tissues. On 
clinical grounds, he states, there is considerable support for this, 
at first sight, improbable theory. If the lesion extends at all 
deeply, it leads to the formation of ulcers, which are extremely 
intractable, and they may be due to irritating particles still pre- | 
sent in the tissues. Mr. Gilchrist advises X-ray operators and 
experimenters, who develop any special idiosyncrasy, to abstain 
from their use if they find that the slightest. deleterious results 
follow an exposure to them. 
A NUMBER of valuable works on botany and other branches 
of natural history, from the library of the late Mr. Freeman 
C. S. Roper, were sold by auction last week, the 668 lots 
realising a total of 1308/7. 15s. Among the more important lots 
mentioned in the Zzes, with the prices obtained, are the 
following :—Mr. C. Cooke, ‘‘ Illustrations of British Fungi,” 
1881-91, eight volumes, 17/. 5s. ; ‘‘ The Grete Herbal,” printed 
at Southwarke by P. Treveris, 1526, extremely rare, a sound 
copy, 392; a set of the Ray Society publications from the 
commencement in 1845-1893, 282. ; P. A. Saccardo, ‘* Sylloge 
Fungorum,” 1882-96, 27/.; the Yournal of Botany from its 
NO. 1432, VOL. 55] 
The movements of the | 
commencement in 1863 to £896, 21/.; J. Sowerby, ‘‘ English 
Botany,” 1790-1863, with the Rev. M. J. Berkeley's appendix 
volume on British Algae, 36/. ; another of the same work, but 
the third edition, 1863-92, 157. ros. ; ‘‘ Bryologia Europa,” a 
work on mosses by Bruch, Schimper, and Giimbel, 1836-64, 
182. 5s.; Transactions of the Zoological Society, 1835-95, 
432. Ios. 
THE Dazly Chronicle announces that the preliminary arrange- 
ments are now completed for laying across the English Channel 
two additional telephone cables. The first cable will be laid 
shortly by the English cable ship JZonarch, the second being 
laid by the French Government, for whom it has been con- 
structed in France. The cables will leave the English side of 
the Channel about three miles to the west of Dover. There are 
two circuits in each wire; so that, with the cable already laid, 
there will be six wires available for public use instead of two, as 
at present, which are in constant use. When the additional 
cables are duly installed, it is stated that facilities for inter- 
national telephoning will be given to the large commercial 
centres in both England and France, instead of confining them 
to London and Paris only, as at present. When the two new 
cables are laid, there will be in all about thirty-four wires across 
the English Channel between St. Margaret’s, Dover, on the 
east, and Beachy Head on the west. 
Four hundred years ago the Atlantic was crossed for the first 
time by Cabot, and a little later Vasco da Gama started on his 
first voyage to India round the Cape of Good Hope. As the 
fourth centenary of these epoch-making expeditions will shortly 
be celebrated in Bristol, Canada and Portugal, an article upon 
them, by Mr. Edward Salmon, in the current number of the 
Fortnightly Review, appears at the right psychological moment. 
It is generally believed that Sebastian Cabot was the captain of 
the English ship which first touched the new continent, but 
attention is called to Mr. Henry Harrisse’s work on ‘‘ John and 
Sebastian Cabot,” in which it is shown that Sebastian was an 
impostor who took gredit for what his father, John Cabot, did. 
Furthermore, according to accepted opinion, Cabot struck land 
at the easternmost point of Cape Breton, but Mr. Harrisse con- 
cludes that the first point reached was Cape Chudleigh. John 
Cabot left Bristol for the voyage west in May 1497, with one 
small vessel and a crew of eighteen men; Vasco da Gama lef 
Lisbon, after elaborate preparations, on July 8 in the same 
year, in charge of three vessels. He arrived at Mozambique in 
March 1498, and went from there to Melinde. Leaving 
Melinde he proceeded across the Indian Ocean, and in three 
weeks arrived in India, whether off Calicut or Cananor is 
doubtful. A few other interesting points on the voyages of 
Cabot and Vasco da Gama will be found in Mr. Salmon’s 
opportune article. 
THE latest issue of the Zzvestza of the Russian Geographical 
Society (xxxii. 4) contains a very well-written account, by P. 
Kx. Kozloff, of the last portion of Roborovsky’s Tibet expedition. 
While the main body of the expedition was returning from the 
Nan-shan Mountains, v2é Hami, to the Russian post of Zaisan, 
Kozloff made three very interesting side-journeys across East 
Tian Shan, and in the adjoining deserts. During one of those 
journeys he crossed the Kobbe sand desert, which was once 
visited by Prjevalsky, and lies in the Dzungarian depression, 
between East Tian Shan and the Altai. The wild camel, the 
wild horse (Zgzus Przewalskzz), and the kulang still live in 
numbers in the Kobbe desert. As to man, only a few Kirghiz 
shepherds visit it. From these shepherds, as well as from the 
inhabitants of the Urungu valley, Kozloff heard about the wild 
men (Ays-kzyzk) who are said to live in that desert; and 
although the Russian explorer does not much trust to the rich 
fancy of the nomads, he nevertheless faithfully reproduces what 
