SOs 
NATURE 
[JuNE 6, 1912 
been replaced by machines in northern England, and 
have quite gone out of use. Mr. Ling Roth, in the 
eleventh Bulletin of the Bankfield Museum, Halifax, 
has collected much curious information about this 
obsolete industry. The card, mounted on a handle, 
consisted of a piece of leather into which teeth 
formed of bent wire were inserted. The implements 
used in the manufacture were of a very rude 
character, and the work was done at exceedingly low 
rates of wages, some being sent from Halifax to 
Gloucestershire, where the rate of child labour 
employed in fixing the teeth was 1600 for a half- 
penny. The machines now in use are able to set 
400 ‘“‘staples’’ in a minute. 
Tue tenth number of vol. iv. of Records of the 
Indian Museum is devoted to a supplement to Mr. 
E. Brunetti’s catalogue of Oriental gnats and mos- 
quitoes (Culicidz), such an addition being rendered 
necessary by the amount of recent work on the sub- 
ject. The author takes occasion to protest against 
the great splitting of genera and species—and like- 
wise the formation of groups regarded as of super- 
generic value—which forms such a marked feature 
in most of this work. He also objects to the practice 
of allowing the female to be regarded as the type of 
a species in cases where males and females presumed 
to be specifically identical have proved distinct; the 
obvious remedy is for describers to cite one particular 
specimen as the type of every new species. 
In vol. Ixili. of Videnskabelige Meddelelser f. d. 
Nat. For. i Kjébenhavn, Dr. J. C. Nielsen gives an 
account of the larva of a dipterous fly infesting the 
nestlings, and in some cases also the adults, of South 
American passerine birds. The parasites, which 
were ‘collected in Concepcion, Argentina, are found 
in large tumours situated on the abdomen of the 
victims, and appear to be in some cases fatal to 
nestlings, although it is uncertain whether the same 
result follows in the case of full-fledged birds. Flies 
have been bred from the maggots, and prove to 
belong to the species now known as Mydaea 
anomala, which was originally described in 1867. 
The eggs, or more probably the young maggots, are 
deposited by the fly on the bird, and the latter sub- 
sequently bore their way through the skin of their 
host by means of an unusually powerful biting 
apparatus. In Europe the larve of the fly Proto- 
calliphora azurea are said to infest pipits, sparrows, 
and swallows, but the only other definitely recorded 
instances of such parasitism elsewhere are from 
South America and the West Indies, the parasite in 
most or all of these cases being probably identical 
with the one described by Dr. Nielsen. 
WE have received from the U.S. Weather Bureau 
its useful meteorological charts of the great oceans 
and lakes for June (those for the South Atlantic and 
South Pacific include the winter season, June to 
August). The chart for the North Atlantic contains 
a special note on the safe routes to be taken by 
vessels trading between northern Europe and Boston 
or New York to escape drift ice and icebergs in 
various months. In the month of June shipmasters 
NO. 2223, VOL. 89| 
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| of Illuminants” 
_ Progress directs attention once more to the very low 
are cautioned to'‘cross the forty-second meridian of 
west longitude so far south as latitude 38° 20’ north. 
We need scarcely mention that the mean limits of ice 
are also carefully laid down on the monthly charts 
issued by the English and German departments deal- 
ing with maritime meteorology. 
OBSERVATIONS of the brightness of the sky have 
frequently been made for the parts of the sky at 
some distance from the sun, chiefly with the view of 
explaining the origin of their blue colour and, in 
later times, to test the theory which ascribes the 
colour to the molecular scattering of the incident 
sunlight. In a recent dissertation, from which he 
has sent an extract, Dr. H. Diercks, of the Potsdam 
Observatory, discusses measurements of brightness 
in the immediate neighbourhood of the sun, made by 
him at the Physikalisches Institut at Kiel. The 
measurements were comparative, the brightness of 
the sun’s disc being taken as 100,000. In an ex- 
ample quoted, the values of the brightness in round 
numbers on a clear day fell from 240 at a distance 
of 18’ of arc from the sun to 140 at 1°, 70 at 2°, 30 
at 3°, 16 at 4°, and 11 at 7°. The principal con- 
clusions derived from the observations are :—(1) the 
brightness falls off regularly with increasing distance 
from the sun and in a symmetrical way; (2) it 
depends upon the altitude of the sun, an increase in 
altitude corresponding with a decrease in relative 
brightness; (3) for the same altitude the brightness 
diminishes as the blue of the sky increases in 
intensity: the smallest relative values obtained for 
the brightness near the sun during the course of the 
observations were about one-fourth of those quoted 
above; (4) the values of the relative brightness supply 
a very sensitive criterion of the purity of the atmo- 
sphere. The results suggest that the illumination is 
due either to ice crystals in the upper atmospheric 
layers or to dust in the lower atmosphere. 
Mr. Dow’s article on the “Luminous Efficiency 
in the current number of Science 
efficiencies attained, even in the best technical prac- 
tice, and the vast field that is still open for further 
improvements. The luminous efficiency of the in- 
verted gas-mantle is about 0-5 per cent., as against 
5-4 per cent. for the tungsten filament electric lamp 
and 13:2 per cent. for the flame arc. But the gas- 
lamp has the advantage that the total radiation, on 
which the above percentages are calculated, is paid 
for at a much lower rate than in the case of elec- 
| trical energy, and the existing ‘“‘ waste” of 99:5 per 
| cent. leaves a large margin for future economies. 
It has been calculated that a “white” light covering 
the whole spectrum could be produced theoretically 
at the rate of 26 candle-power per watt, or light in 
the bright yellow-green region at 65 candle-power 
per watt, as contrasted with the 4-5 candle-power 
per watt of the best flame-arcs. The wave-length of 
maximum radiation decreases as the temperature of 
| the source increases; in sunlight, perhaps as a sequel 
to many generations of natural selection, the maxi- 
| mum agrees with that of visual intensity, but all 
artificial sources give maxima in the infra-red; 
