476 
revolutionary conclusion. Dr. Daniell does not care 
to debate whether the shift of interference bands 
expected by Michelson is likely to occur, or whether 
the smaller value elaborately worked out towards the 
end of his life by Prof. Righi of Bologna is more likely 
to be correct. For according to him it is not the shift 
of bands that is important, but the fact that such 
bands appear at all. He has convinced himself that 
in the Michelson experiment no interference bands 
ought to appear unless there is an enormous relative 
motion between earth and ether. Hence, from the 
fact that interference bands do appear in every 
repetition of the experiment, Dr. Daniell concludes 
that such relative motion, amounting to 12,000 miles 
a second, is proved to exist. As the interference 
part of the Michelson- Morley experiment is of a 
straightforward and elementary character, it is 
difficult to understand how Dr. Daniell can have 
persuaded himself, and can seek to persuade others, 
that a motion of the ether is necessary in order 
to account for the appearance of interference bands 
when a beam of light is split into two halves and after- 
wards reunited. The premises upon which this de- 
duction is based are not clearly stated in the article, 
though several equations are given from which it is 
apparently deduced, but they must include an error 
which Dr. Daniell has overlooked. 
Sir ArtHUR KerrTH, in the first of his Hunterian 
Lectures on “‘Man’s Posture: its Evolution and 
Disorders,’ which appears in the British Medical 
Journal of March 17, reviewed the results of recent 
investigations which throw fresh light on how, when, 
and where man came by his erect attitude. He 
pointed out that extinct forms of man indicate that 
the upright carriage of the head was evolved later 
than the human form of the lower limb, of which 
the origin must be sought in Miocene or possibly 
Eocene times. He distinguished three phases of 
evolution. In the hylobatic phase the gibbon was 
differentiated from its cousins, the Old World and 
New World monkeys, by postural adaptations of 
bones and muscles in virtue of which it was ortho- 
grade and human in type as opposed to the pronograde 
monkeys. This differentiation probably took place 
towards the end of the Eocene period. The troglo- 
dytic phase was represented by the great anthropoid 
apes, evolved from the small anthropoids probably 
in pre-Miocene times. In the plantigrade phase, 
structural changes were confined almost entirely to 
the lower limbs. Seeing that man shares so many 
characters in common with the great anthropoid apes, 
Sir Arthur Keith held that man must be regarded 
as one of several aberrant branches of one great stem 
which began to break up into the various fossil and 
living forms at the beginning of the Miocene or the 
end of the Oligocene period. 
Visitors to Kew during the next few weeks should 
make a point of seeing a special exhibit of sports 
requisites arranged in Museum IV., the Museum 
devoted to British forestry. In this exhibit are to 
be seen cricket bats, tennis and badminton rackets, 
croquet mallets and balls, hockey sticks, and other 
NO. 2788, VOL. 111] 
NATURE 

[APRIL 7, 1923. 
articles in various stages of manufacture. Special 
interest is attached to the cricket bat, for, among 
the many thousands of woods known to science 
(upwards of 5000 kinds are represented in the Kew 
collections), no wood has been found that makes a 
suitable substitute for the best English willow (Salix 
cevulea) for the blades of bats. The material for 
the handles cannot be grown in the British Isles ; 
that is the product of one or more tropical palms, 
Calamus spp. (Sarawak Cane). The heads of hockey 
sticks, the frames of tennis and badminton rackets, 
cricket stumps, and the handles of croquet and polo 
mallets are made of the best British ash, while 
croquet balls are often made of beech, and polo balls — 
of willow. Various other articles are shown, but those 
mentioned suffice to indicate how dependent the 
sport-loving public is upon the home-grown timber 
industry. 
Tue Director of the U.S. Coast Geodetic Survey 
announces that Congress, at its recent session, made 
an appropriation of two thousand dollars to the State 
department for the support of the International 
Latitude Observatory at Ukiah, California, during 
the fiscal year 1924, or until some other provision is 
made for that station. In the estimates for the Coast 
and Geodetic Survey for the fiscal year 1924 there 
was included an item which, if it had been approved 
by Congress, would have authorised that bureau to 
carry on the variation of latitude observations at 
Ukiah as a part of its regular geodetic work. It is 
hoped that this authority will be granted during the 
next session of Congress in order that there may be © 
no possibility of a break in the observations for 
variation of latitude which have been made con- 
tinuously at Ukiah for the last twenty-three years. 
WHILE the specification and measurement of arti- 
ficial light has been brought to a very fair state of 
precision, there has, until recently, been little corre- 
sponding advance in dealing with natural illumina- 
tion. The chief work in this field has been in con- 
nexion with the design of windows for schools, and 
an exhaustive report on this subject was issued by 
a committee of the Illuminating Engineering Society 
shortly before the war. A very complete survey of 
natural lighting, accompanied by an account of some 
highly interesting methods of measurement, was 
presented by Messrs. P. J. and J. M. Waldram at the 
meeting of the Illuminating Engineering Society on 
March 27. These methods are based on the relation 
between the value of unrestricted outdoor daylight 
illumination, and the illumination at a specified point 
in a room, a factor which should be substantially 
independent of climatic conditions and should serve 
as an indication of the access of daylight. Of special 
interest was the account of methods of estimating 
the effect of obstructions to light and the predeter- 
mination of daylight-access in buildings. These have 
recently proved extremely valuable in ancient light 
cases. Mr. J. W. T. Walsh gave some account of the 
work on parallel lines being done at the National 
Physical Laboratory, and paid a high tribute to the 
experimental skill revealed in the paper. 
