
3 May 5, 1923] 
death from apoplexy, early in the year. The long 
list of his papers, from 1877 onwards, and the apprecia- 
tion so aptly written in English by Prof. A. G. 
Hégbom, show how greatly geological science has lost 
by the passing of one who did not cease to be an 
investigator when he could also afford to be a patron. 
The Bulletin is prefaced by a portrait that will record 
Sj6gren’s truly noble personality for friends in every 
quarter of the globe ; it is difficult to realise that he 
was already well on his way towards his seventieth 
year. The volume covers even a wider range than 
usual, from the crystallography of amphibole to 
Cretaceous mosasaurs from Texas. We may specially 
note G. Frédin’s elaborate study of the highlands of 
central Sweden, including the Are district, written in 
German, and his paper in English ‘‘ On the analogies 
between the Scottish and Scandinavian portions of 
the Caledonian mountain-range.’’ In the latter, as 
the result of his studies of deep continuous sections 
in Sweden, the author urges that the Moinian and 
Dabradian complexes in Scotland received their meta- 
morphic characters during the Caledonian movements, 
and that they are formed of Torridonian (Sparagmite) 
and early Paleozoic formations, rather than of a 
pre-Cambrian series metamorphosed before Paleozoic 
times. However much this conclusion might simplify 
the stratigraphy of certain areas, it seems incom- 
patible with the known unconformity of unmeta- 
morphosed Ordovician beds on Dabradian schists and 
quartzites in western Ireland. 
Om Fietps AND THE GRAVITY BALANCE.—The 
recent use of the Eétvés gravity balance by the oil 
a in prospecting for new and exploring old 
oil fields has brought into prominence an extremely 
sensitive instrument devised nearly thirty years ago by 
Baron EGtvés, professor of physics at Budapest, and 
constructed in 1888 by Siiss, then director of the 
mechanical training workshops of Budapest. The 
instrument and the measurements made by means of 
it were described in Hungarian periodicals in 1890 but 
were not generally known till 1896, when a short 
account appeared in the Annalen der Physik, vol. 59, 
p. 354. An instrument has now been acquired for 
the Science Museum at South Kensington, and a paper 
by Messrs. H. Shaw and E. Lancaster- Jones describing 
it and giving its theory and some account of tests made 
by means of it, appears in the April issue of the Pro- 
ceedings of the Physical Society of London. The 
instrument consists of a fine fibre which supports a 
horizontal rod, to one end of which a small mass is 
directly attached, while from the other an equal mass 
is suspended by a second fine fibre. The instrument 
determines the difference of the values of gravity at 
the two masses, and according to Eétvés will detect a 
difference of 1 x 10° C.G‘S., unit. 
MAGNETIC RECORDING DRUM FOR ELECTRIC RE- 
LAys.—It is now becoming increasingly difficult to 
differentiate between telegraph, telephone, and radio 
engineers. The paper read by Dr. N. W. McLachlan 
to the Radio Section of the Institution of Electrical 
Engineers on April 11 illustrates this. It is entitled 
“The Application of a Revolving Magnetic Drum to 
Electric Relays, Siphon Recorders, and Radio Trans- 
mitting Keys,” and it is of equal interest to every 
kind of communication engineer. When the drum is 
magnetised, part of it is pressed on fixed iron rings 
with considerable force, and this alters the speed. 
The author finds that the tangential pull thus ob- 
tained is many times greater than the product of 
pressure due to the product of the magnetic attraction 
and the coefficient of friction. The ratio of the experi- 
mental pull to the calculated pull may exceed 50. 
NO. 2792, VOL. 111] 
NATURE 
Hjalmar Sjégren as its editor; but it also records his 
617 
It is suggested that the operation of the device depends 
on some form of cohesive action brought into play 
by magnetism. 
Upper Air Data IN AMERICA.—Free-air winds at 
Lansing, Michigan, are dealt with by Mr. C. L. Ray, 
of the U.S. Weather Bureau, in the U.S. Monthly 
Weather Review for December 1922. Pilot-balloon 
observations have been carried out at this station 
daily since June rorg, flights having been made for 
more than two years at 7 A.M. and 3 P.M., except when 
impossible through bad weather. Latterly, observa- 
tions have only been made at 3 P.M. For the three- 
year period, the results are given for the four seasons 
of the year for various altitudes from the surface to 
6000 metres, and the percentage of the winds from 
various directions is shown. More than 50 per cent. 
of the surface winds have a south component and 
more than 56 per cent. have a west component. At 
4000 and 6000 metres the preponderant direction lies 
between west and north-west. The variation of the 
winds with altitude for each season is given by tables 
and graphs. Surface velocities average about three 
metres per second. At 250 metres the velocities 
average two and a half times greater than at the 
surface. Above 1500 metres, winds are consistently 
west to north-west. Velocities are greater in the 
winter months, and at the 6000 metre elevation the 
average reaches 27-7 metres per second as compared 
with the summer mean of 12 metres per second at that 
level. In the upper levels the easterly winds do not 
teach the velocities attained by the westerly winds. 
Winds with a surface south component all show a 
clockwise movement with altitude and generally have 
a west-south-west direction at about 2000 metres. 
There is a more or less persistent north component 
to the highest levels. The highest velocity reached at 
Lansing was 83 metres per second from the north-west 
at an altitude of about 7000 metres on December 17, 
1910. 
IcE PATROL SERVICE IN NorTH ATLANTIC.—The 
U.S. Monthly Weather Review for December 1922 
contains an article by Lieut. E. H. Smith on ‘“‘ Some 
Meteorological Aspects of the Ice Patrol Work in the 
North Atlantic.’’ The disaster to the s.s. Titanic on 
April 14, 1912, when what was then the largest ship 
afloat was sunk by striking an iceberg off the tail of 
the Great Bank of Newfoundland, resulted in an ice 
patrol being established with the object of preventing 
the recurrence of a similar loss. The patrol was of 
International origin, the management of the service 
being undertaken by the U.S. Government. It is 
now about ten years since the service has been in 
operation, and much information has been gathered 
as to the determination of the variable limiting lines 
of menacing ice, and efforts have been made to 
determine the causes of the variations as to seasonal 
and other differences. Glaciers on the west coast 
of Greenland are said to be the great source of icebergs 
which appear during March drifting south along the 
east side of the Great Bank, and during April, May, and 
June they constitute a menace to steamships. The 
summer winds in West Greenland, the birthplace of 
the bergs, have an immense influence on the number 
of bergs over the North Atlantic in the following 
season. Off-shore winds drive a great number of 
bergs westward into the southerly current, while on 
the other hand, on-shore winds tend to cause a poor 
ice year. It is said to take approximately five months 
for a berg passing Cape Dyer to appear south of the 
45th parallel. If the dates of the bergs passing Cape 
Dyer were known, long-range forecasting of ice con- 
ditions in the North Atlantic would probably be 
possible. 
