8 NATURE 
[May 4, 1899 
BETIERS LO THEVEDIT Ole: 
(The Editor does not hold himself responsible for opinions ex- 
pressed by his correspondents. Netther can he undertake 
to return, or to correspond with the writers of, rejected 
manuscripts intended for this or any other part of NATURE. 
No notice zs taken of anonymous communications. | 
The Chief of the American Nautical Almanac. 
PAGE 542 of the issue of NATURE for April 6 contains an 
announcement that Dr. T. J. J. See has been nominated as 
Chief of the American Nautical Almanac Office ; but as this is 
entirely erroneous, I venture to hope you will correct it. Prof. 
See has been assigned to a subordinate position in the Naval 
Observatory, and has nothing whatever to do with the Nautical 
Almanac Office. Wm. HARKNESS. 
Nautical Almanac Office, 
U.S. Naval Observatory, Washington, April 18. 
[The announcement referred to by Prof. Harkness was based 
upon information given in Scéewce, and was corrected in the 
following number (p. 562) upon the authority of the same journal. 
—Ep.]. 
Wehnelt Interrupter. 
IN a previous communication to this journal (p. 438), I 
pointed out various methods of controlling the Wehnelt inter- 
rupter with a view to preventing the destruction of Crookes’ 
tubes. Since then I have made a series of observations which 
confirm what was previously stated. The principle upon which 
the experiments were conducted was to keep all the factors 
constant with one exception, the amperage, voltage, results 
upon the fluorescent screen and photographic plate being care- 
fully noted and registered by means of an X-ray meter. In one 
set of experiments the voltage was varied, in another the density 
of the solution, in the third the size of the platinum, in the 
fourth the self-induction of the primary coil. By varying any of 
these, or by a combination specially suited for different pur- 
poses, complete control of the Wehnelt was obtained in the way 
of greater or less fluorescence, actinic power, and steadiness of 
the screen. Briefly stated, it was found that all these effects 
decreased as we lowered the voltage, the self-induction of the 
primary, the density of the electrolyte, and the size of the 
platinum. 
Early in these investigations, great differences between the 
readings across the Wehnelt and those across the terminals of 
the primary were observed, for the most part indicating increase 
in the former. An extended series of observations was made by 
means of Lord Kelvin’s electrostatic voltmeters and ampere 
gauge, and a relationship between all the different factors was 
clearly demonstrated. Different induction coils were used, in 
one of which the self-induction could be altered by withdrawing 
the soft iron core. Briefly put, it may be said: (a) that there 
was a corresponding decrease in the readings across the Wehnelt 
as the voltage in the primary decreased ; (4) different con- 
ditions, such as length of spark gap, or different vacuum in the 
Crookes’ tube placed in the secondary circuit, affected the read- 
ings considerably ; (c) the increased voltage across the Wehnelt 
seemed to depend upon the amount of self-induction in the 
primary. In this group of experiments, it was noted that, as the 
self-induction increased, the voltage increased, the amperage 
decreased, and the number of interruptions also decreased. A 
non-inductive resistance was made with a view of confirming the 
results, and it was used instead of the primary of the ordinary 
coil. In this there was, however, sufficient self-induction to 
work the Wehnelt under certain conditions. With this arrange- 
ment, not a single reading across the Wehnelt was higher than 
that of the voltage across the primary. J. MACINTYRE. 
Glasgow, April 28. 
Polarisation Experiment. 
By the following simple arrangement a single pile of glass 
plates may serve at once as polariser and analyser, and be used 
to study or to exhibit on a screen the interference colours with 
mica or crystal sections. It may not be new, but I have not 
seen it given anywhere. A beam of light is reflected down from 
a pile, polarised in the plane of reflection. Passing through a 
double-refracting crystal, it is resolved and then reflected by a 
common mirror under the crystal. On passing through the pile, 
NO. 1540, VOL. 60] 
which polarises by refraction in a plane at right angles to the 
plane of first polarisation, it shows the interference colours. 
Using sunlight and interposing a convex lens, we may by this 
simple means project the interference rings of crystal sections. 
Central College, Bangalore, India. J. Cook. 
Gecko Cannibalism. 
A FEW days ago, on opening the stomach of a young female 
gecko (Gecko monarchus, a species which occurs fairly com- 
monly in the compound outside our bungalow here), it was found 
to contain, in addition to a caterpillar and some other remains 
which I could not identify, a smaller gecko of the same species 5 
this, judging from its position in the stomach, had evidently 
been eaten head foremost, and was quite entire. 
The lengths of the two individuals were : 
Anders { Tip of snout to cloaca, 57 mm. 
Larger individual \ei(Gall Grokentern 
{ Tip of snout to cloaca, 32 mm. 
"| Tip of snout to tip of tail, 74mm. 
Giinther, in his ‘‘ Reptiles of British India,” alludes to 
geckos as being known to destroy ‘‘the younger and weaker 
members of their own species,”’ and he describes the individuals 
of Gecko monarchus as ‘‘ pugnacious among themselves ”; but 
the fact that an animal will prey upon another of its own species. 
while living under completely natural couditions and with an 
abundant supply of its normal insect food seems worth 
recording. F. P. BEDFORD. 
Singapore, March 23. 
Smaller ditto 
‘Asia, the Land of Rice.” 
THROUGH the medium of your pages I would ask, Can any 
of the numerous readers of NATURE give information as to how 
or from what origin the name Asia came to be applied to a large 
portion of the earth’s surface? Did it in olden times belong 
more especially to that district which we now term India? Was 
the name Asia used by any race of people to denote the land of 
spices and other valuables, whose products were brought by 
caravan across Persia and onward by way of the Red Sea? 
In the last number of the /oznal of the Polynesian Society 
(vol. vii. 185) an interesting paper, by Mr. S. Percy Smith, the 
Surveyor General for New Zealand, is published, ‘‘ Hawa-iki = 
the whence of the Maori,” in which he shows that Polynesian 
traditions tell that the Maori people of New Zealand originally 
started on their migrations through the isles of the Pacific from 
a large country which they name ‘‘ Atia-te-varinga.” 
“*In Madagascar, the name for rice is varz cr vave ; in Sunda 
(Java), Macassar, Kolo, Ende, rice is fave ; in the Bima tongue 
it is fave; in Malay it is fadzZ and farz. Itis stated that the 
Arabs changed the original Malay f into /, so that originally 
the Malay name was fa77z.”—‘‘ It is sufficiently clear from the 
above that vavz means rice, and the Rarotongan tradition is 
correct, though not now understood by the people themselves.’ — 
“Tt would seem from this that Atia was a country in which the 
rice grew, and the name Atia-te-varinga may be translated Atia- 
the-be-riced, or where plenty of it grew.” 
In the word varzzga the suffix mga is significant of the plural, 
and so we get ‘‘ Atia the rice-growing land.” 
Tayitor WHITE. 
Wimbledon, Hawkes Bay, N.Z., February 9. 
RECENT SCIENCE IN ITALY. 
VAN BRIEF survey of recent numbers of the 77avsac- 
Zions published by the Reale Accademia dei 
Lincei, or by the various other Italian Royal scientific 
academies, will amply show that the country to which we 
are indebted in the past for the telescope, the mariner’s 
compass, the voltaic cell and other equally valuable inven- 
tions, is keeping well to the fore in all advancements of 
modern science. 
In mathematics there have appeared, during the year 
1898, papers by A. Brambilla on Steiner’s surfaces, and on 
the surfaces of Veronese, also on the principal polygons 
of a gibbous quartic with a double point ; while G. Gal- 
lucci has dealt with tetrahedra inscribed in a gibbous 
