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4 
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FEBRUARY 24, 1923] 
NATURE 
269 

_ expedition, of which ten are new records, one being 
also new to science, but even this species shows no 
striking variation from already known European 
_ varieties. A list is given of mosses identified by Mr. 
H. N. Dixon, with their localities and details of the 
rotifers and tardigrades they harboured. The new 
species of rotifer and a new parasite are described 
and figured. 
FUMAROLES IN ALAsSKA.—A volcanic eruption on 
a great scale in June 1912 smothered in half a foot 
of ashes the town of Kodiak in southern Alaska. 
This was traced to the Katmai volcano about 100 
miles to the west in the long Aleutian chain of vol- 
canoes. In 1915 the U.S. National Geographic Society 
sent a preliminary expedition to examine the region. 
The next year a larger expedition discovered to the 
west of Mount Katmai the remarkable valley of 
_ the Ten Thousand Smokes which was explored in 
1917, 1918, and especially 1919. These explorations 
were conducted by Dr. R. F. Griggs, who describes 
them in “The Valley of Ten Thousand Smokes” 
{National Geographic Society, Washington). The 
valley, which has an area of about 30 to 40 square 
miles, is floored with Jurassic sandstones and shales 
overlain in places by volcanic rocks. Lines of 
fumaroles skirt the sides and cross the valley to the 
number of 10,000 or more. The fumaroles generally 
_ have a temperature of 200°C. to 300°C., but some 
records of over 500° C. are given. Analyses of the 
ases showed steam to be the principal constituent, 
ut appreciable quantities of hydrofluoric acid were 
present. From earlier accounts of the district it is 
clear that these volcanic manifestations in the valley 
date from the eruption of Katmai in 1912. The 
text is admirably illustrated by photographs, maps, 
and coloured plates, and gives a full account of the 
valley and the work of the expeditions. It is written 
in a popular vein but embodies a great deal of scientific 
interest. The study of the vegetation in relation to 
the ash deposits is of particular value. The valley 
with Mount Katmai and the surrounding country, 
to the extent of 1700 square miles, has been declared 
by the United States Government a “ National 
onument ”’ reserved from settlement or exploitation, 
BACTERIA AND TRAVERTINE.—An interesting case 
of the promotion of rapid deposition of travertine 
by bacterial action has been described at some 
length by Mr. John Parry in a lecture given before 
the Diamond Fields Mining Institute at Kimberley, 
S. Africa (Report in Chemical News, vol. 125, pp. 225, 
241, and 257, 1922). The organisms, which are 
compared in their action with Drew’s marine Bacillus 
calcis, occur in water streaming down the shafts 
of Kimberley mines, and they produce deposits of 
fibrous calcium carbonate in iron pipes and crusts 
on planks and tunnel-floors. These deposits have 
a lustrous black surface, which is attributed to 
organic matter derived from decaying timber in 
the mines. Evaporation clearly plays no part in 
the accumulation. 
Tue Upper Arr ‘In [NpDIA.—A presidential address 
by Mr. J. H. Field to the section of physics and 
mathematics of the eighth Indian Science Congress 
on “ The upper air: objects and methods of research 
in India,”’ is printed in the Proceedings of the Asiatic 
Society of ngal, vol. xvii., 1921, No. 4. The 
subject of the address was chosen as the science 
of meteorology has during recent years attracted 
to its side physicists and mathematicians of eminence 
who are rapidly evolving order out of chaos. In 
contrast to the temperature changes experienced 
at the ground by day and night during summer and 
winter, it was pointed out that at the height of half 
NO. 2782, VOL. 111} 
a kilometre (1640 ft.) India enjoys an equable 
temperature throughout the twenty-four hours. 
‘Similarly with wind, both in direction and force, 
great changes very commonly occur within the 
lowest layer. Passing upwards through a range of 
many kilometres, the temperature, which has been 
falling more or less steadily to very low values, shows 
a sharp halt in its rate of fall, or the “ lapse-rate”’ 
suddenly becomes zero. This startling change occurs 
in India at a height of about 10 kilometres ; near 
the equator it lies at about 17 kilometres, and from 
the equator it falls continuously with increasing 
latitude toward the poles, where it seems to lie at 
a height of about 7 kilometres. Reference is made 
to observations of the upper air carried out in India 
by means of free-flying balloons and the theodolite 
and by means of balloons and kites carrying self- 
recording meteorological instruments ; many clever 
devices have been introduced to adapt the observa- 
tions to Indian climate. The solution of rainfall 
problems in India is alluded to as a matter of life 
and death, controlling as it does the dread spectre 
of famine. It is the business of the Indian meteoro- 
logist to forecast with all possible speed the rains 
both in the monsoon and in the cold weather. 
THE GREEN Ray.—Instructor Lieut.-Commr. F. W. 
Shurlock, R.N., of H.M.S. Royal Sovereign, sends the 
following notes describing observations of the green 
ray: At Vigo, on January 21 and 22, the sun set 
behind an island. On January 21 one tip of the 
disappearing segment showed the green tint, while 
the other was indistinct, probably owing to irregular 
refraction. On January 23 the disc was red and 
changed to magenta. At sea, off Oporto on January 
24, the two tips were green. The green portion 
broke up into irregular patches with colours re- 
sembling those of soap films. Just after sunset a 
row of irregular yellow patches appeared over the 
place where the sun’s rim was last seen. At sea, off 
Cape St. Vincent on January 25, the sky being clear 
and the sun a golden yellow, a typical example was 
observed. The green colour started from the tips 
and flooded the exposed part of the disc. After sun- 
set, a small diffuse patch of pale green appeared 
immediately above the place where the sun set and 
faded almost at once. The whole effect lasted about 
three seconds and was seen by a group of trustworthy 
observers. It is interesting to note that with a 
telescope (x30) the green afterglow was distinctly 
seen; with binoculars (x6) it was faintly seen ; 
while unaided observers failed to detect it. 
An ImprRoveD HyGroscope.—Messrs. Negretti and 
Zambra have devised an improved hygroscope which 
indicates at a glance the percentage of moisture in 
the air. The hair hygrometer was originally con- 
structed by Saussure, who used a hair to indicate 
changes of moisture, the hair elongating when 
moist and. contracting when dry. Considerable im- 
provements have been made by Messrs. Negretti 
and Zambra, and twelve or more hairs form the 
basis of the new instrument ; human hair is specially 
selected and scientifically treated. The hairs are 
anchored by their lower ends and the upper ends 
are connected to a link which operates on a lever 
attached to the pointer spindle. The dial is graduated 
from 10 to 100 in percentage relative humidity. 
Readjustment of the instrument, if required, is quite 
simple. On the lower part of the dial is a scale to 
ascertain the dew-point if required. It is claimed 
that the instrument will be of especial value in many 
industrial processes, and various types are manu- 
factured depending on the requisite conditions. A 
large type of the same instrument combined with 
a dew-point hygrometer has also been devised. 
