NovEMBER 13, 1913] 
NATURE 
327 
1913. This ring was placed on a nestling swallow 
by Mr. R. O. Blyth, at Skelmorlie, Ayrshire, on July 
27, 1912. A few months ago an adult swallow ringed 
in Staffordshire was recorded as having been captured 
near Utrecht, Natal, in December, and the present 
record is from about one hundred and fifty miles 
west of that place, which is not far in 
comparison with the total length of the 
journey. Mr. Witherby adds:—‘‘In writing of the 
Natal record I expressed surprise that a swallow 
breeding in the far west of Europe should migrate 
so far east in South Africa, but now that Dr. Hartert 
has shown by his observations in the middle of the 
Sahara that deserts are not necessarily a bar to the 
passage of migrating birds, as was formerly sup- 
posed, it may perhaps be presumed that these swallows 
take a more direct line than one would previously 
have thought possible.” 
THE monthly meteorological chart of the North 
Atlantic for November (first issue), published by the 
Meteorological Office, contains daily maps showing 
the distribution of air-pressure, wind, &c., for October 
10-16. These exhibit at the beginning of that period 
low-pressure systems extending from beyond the Great 
Lakes’ region of North America to Central Asia. The 
central area of the most important of these disturb- 
ances lay near latitude 53° N., longitude 27° W. It 
was in the heavy gales associated therewith that the 
ill-fated steamship Volturno was abandoned on Octo- 
ber 10, near latitude 48° N., longitude 34° W. (see 
Nature, October 16). The Meteorological Office re- 
port states that the effects of the storm were felt in 
a modified degree on the western coasts of the British 
Islands, the wind reaching gale-force at a few exposed 
points. 
SomE interesting observations that promise to throw 
a much-needed light upon several problems in the 
later geological history of Northumberland and Dur- 
ham were described at the opening meeting of the 
Northumberland Coast Club by Mr. S. Rennie Hazel- 
hurst. Mr. Hazelhurst has found in natural and arti- 
ficial exposures at the mouth of the Tyne a series 
25 ft. thick of gravels, sands, clays, and loams 
containing well-preserved plant remains. They are 
traceable over an area of about a square mile, and 
reach an altitude of 100 ft. above the sea. The sug- 
gestion is made that they mark the site of a post- 
glacial lake which is regarded as exceeding in mag- 
nitude any similar lake recognised by its deposits in 
any other part of these islands—a claim that can 
scarcely be maintained in view of Fox Strangways’s 
description of Lake Pickering. The details so far 
published of Mr. Hazelhurst’s observations make no 
mention of their bearing upon the question of the 
alleged raised-beaches on this coast. The local geo- 
logists are unanimous in asserting the existence of a 
well-preserved raised beach in Northumberland and 
Durham at about 150 ft. above sea-level, but most 
outsiders regard the features as of glacial origin. A 
lake at 100 ft. O.D. at the mouth of the present 
Tyne may have preceded, or succeeded, the period of 
supposed submersion, and in either case the relations of 
NO. 2298, VOL. 92] 
\ . 
|; the two conditions may furnish decisive arguments for 
or against the hypothesis of the beaches. 
In ‘‘Mendelism and the Problem of Mental Defect” 
(London, Dulau and Co., Ltd., 1913) Dr. David Heron 
enters into a lengthy and elaborate criticism of some 
of the work of the American Eugenics Record Office. 
In particular the theory that feeble-mindedness is 
caused by the absence of a mendelian factor, and 
therefore behaves when inherited as a simple recessive 
character is shown to be unfounded. The care and 
thoroughness with which Dr. Heron has performed 
the task of writing sixty-two pages of destructive 
criticism are worthy of high praise; but if, as he 
anticipates, ‘‘ jealousy of the work of another labora- 
tory’’ is assigned by some as his motive for doing 
something so unusual, he will only have himself to 
thank. For the whole pamphlet is written in a highly 
provocative way, and seems, intended, so far as pos- 
sible, to wound the feelings of the head of the Eugenics 
Record Office, who is responsible in one way or 
another for most of the work criticised. 
In the August number of Le Radium, M. de Broglie 
gives the results of his observations of the inter- 
ference patterns produced on photographic plates by 
Roéntgen rays reflected from the surfaces of crystals. 
He finds that the positions of the spots obtained by 
reflection from various crystals of the cubic system 
are identical, but that the intensities are characteristic 
of each crystal. The effect of temperatures from that 
of liquid air to a red heat is slight, a diminution being 
just perceptible at the highest temperature. Magnetic 
fields of strengths up to 10,000 appear to have no 
effect on the patterns. M. de Broglie directs attention 
to the close similarity between the patterns produced 
by reflection of Réntgen rays from the surfaces of 
crystals and the patterns produced by transmitting 
light through two crossed diffraction gratings. As a 
general rule each spot shows a number of bands which 
the author attributes to the presence in the crystal 
close to the surface of incidence of regions in which 
the orientation of the crystalline elements varies 
slightly. 
WE have received from Messrs. Watson and Sons, 
Ltd., specimens of a new optical glass, called 
“Spectros.”’ Specialists have long desired a glass 
which would absorb (or cut out) the harmful or irritant 
ultra-violet rays, but which would at the same time 
allow the ordinary visual rays to pass unhindered. 
Hitherto the only lenses employed for this purpose 
have been made of the dark smoked or coloured glass 
so often seen; but unfortunately this glass not only 
absorbs the visual rays to a large extent but also fails 
to cut out the ultra-violet rays. ‘‘Spectros” glass, as 
it absorbs the ultra-violet and part of the red, is of a 
green colour, and is made in six distinct tints. The 
first is so light as to be practically unnoticeable—this 
is used for reading glasses—especially by artificial 
light. The other tints are used as occasion may 
require, and the deepest only in severe cases of 
ophthalmia, snow-blindness, &c. Few people recog- 
nise the harm done to eyes by the ultra-violet light 
| present in bright electric illumination, especially by 
