= (9) 
318 
NATURE 
[FEBRUARY 4, [yo4 
left hand, and have always done so from earliest child- 
hood. Without being able to prove it, I have believed that 
this specialisation of the hands was advantageous. With 
my right hand I cannot draw at all, nor can I write with 
my left, except, of course, as anyone can, very badly. If it 
is a fact that to train the left hand for special purposes, 
such as drawing, is advantageous, this is worth knowing. 
Its theoretical explanation would agree very well with the 
views of Mr. Smith, and it seems to me that there is enough 
probability in the idea to make it worth following up. 
Perhaps some of your readers may be able to throw light 
upon it. T. D. A. COCKERELL. 
Colorado Springs, Colo., U.S.A., January 13. 
Science at Oxford and Cambridge. 
It is very surprising to find Prof. Perry charging Oxford 
with fearing and hating natural science. 
Nearly thirty years ago I was engaged in a cave research 
which involved geology, zoology, and archzology, as bear- 
ing on the cave, its fauna, and objects of human workman- 
ship. One of my colleagues was Mr. W. Bruce Clarke, and 
I derived valuable assistance from Prof. Boyd Dawkins. 
Both these gentlemen took first classes in natural science 
at Oxford. Some years afterwards I investigated the 
dentition of Aplysia. This work was subSequently taken 
up and completed by another Oxford man, Mr. Walter 
Garstang. I had been myself much assisted by the Rev. 
T. R. R. Stebbing, F.R.S., formerly tutor of Worcester 
College, Oxford. 
So far as Cambridge is concerned, in two other subjects 
I took up, viz. sea-waves and petrology, there was no need 
to go outside the university, and I may say that the greatest 
authority on the dentition of gastropods is the Rey. Prof. 
H. M. Gwatkin, who cannot be persuaded to publish a line 
on the subject, to the very serious loss to science. 
From what I can observe the training of both Oxford 
and Cambridge is so excellent that the better men are fit 
to do first-rate work in almost any branch of natural science. 
As I have said, Prof. Gwatkin is the authority on the 
dentition of gastropods, while the author of the treatise 
on molluscs, in the ‘‘ Cambridge Natural History,’’ is the 
Rev. A. H. Cooke, a senior classic. 
Then we find a senior wrangler, who was not a chemist, 
setting up a laboratory at home and discovering argon. 
Then again, we had that wonderful professor of mathe- 
matics, the late Sir G. G. Stokes, illuminating every 
physical subject he approached. I had two correspondences 
with that illustrious worker, in one of which he conducted 
me to the very edge of the known, and concluded with the 
sentence (referring to a paper), ‘* You will be able to judge 
how far what you have observed may be additional to what 
is there given.’’ I think that is the distinction between 
Cambridge research and much modern work. The latter 
is greatly a matter of text-books and the opinions of authori- 
ties. The Cambridge man has conducted you to the 
absolute front before you know where you are, and there 
he leaves you to work alone. That has happened to myself 
repeatedly. The modern school is a little apt to give and 
take opinions. It is as hard to get an opinion out of a 
typical Cambridge man as a direct answer from a Quaker. 
Cambridge has no use for opinions. A. R. Hunt. 
Curious Shadow Effect. 
IN connection with the ‘‘ Curious Shadow Effect ”’ 
mentioned by your correspondent, Mr. H. M. Warner 
(Nature, January 28, p. 296), may I be permitted to direct 
your attention, and his, to a somewhat peculiar “* species a) 
of Brocken which I attempted to describe some years ago 
in the Scottish Mountaineering Club Journal (vol. ii. pp. 
32-33, 1893)? I ask this, not with any idea of replying to 
Mr. Warner’s inquiry, but to ask another question which 
perhaps may be answered at the same time. Referring to 
the above mentioned note, I ask the question, ‘‘ How was 
it that more than one image was visible to each of our 
party?’’ ‘‘ Standing close together, all five or six images 
were visible, all within the wide outer halo; but of course, 
not one of us saw more than one set of concentric rainbow 
NO. 1788, VoL. 69 | 
bands or circles—R.O.Y.G.B.I.V.—and at the lower 
limbs of the halos nothing of our reflections could be seen, 
because we were standing slightly below the dip of the 
ridge.”’ i 
The time of day was between 11 a.m. and noon, and the 
date was November 24, 1903. In Mr. Warner’s case the 
date was still nearer to mid-winter, and the time of day 
“near setting ’’ (i.e. ‘‘ within an hour of setting ’’), and 
therefore considerably after noon, as shown in the sketch 
of position. How are the rays affected by refraction and 
reflection ? 
I have never seen nor heard of a quite similar Brocken, 
so I named him ‘‘ The Brocken of Tarduff’’ (Hill in 
Stirlingshire). Joun A. Harvie Brown. 
Dunipace, Larbert, Stirlingshire, N.B., January 29. 
se 
Subjective Images. 
IN corroboration of Prof. Herbert McLeod’s observation 
(p. 297) as to the bright red appearance of printing when 
the eyes were exposed to the glare of a white chalk road, 
will you allow me to record an effect I have several times 
seen when walking over snow while facing bright sun- 
light? On such occasions every dark object on the snow, 
and even the shadows in small deep depressions in the 
snow, have all appeared to me of a vivid blood-red colour. 
As to an allied point, I should be glad to be allowed to 
ask whether the experience of other observers coincides with 
my own as to the tint of objects seen when the eyes are un- 
equally illuminated. If one eye, right or left, is in full 
light, and the other shaded (the hand will give shadow 
enough), then, by closing the eyes alternately, I always find 
that the field of vision of the shaded eye is of a distinctly 
warmer tint than that of the eye in full light. If, as Sir 
Michael Foster says, both eyes respond equally to a stimulus 
applied only to one, then the explanation which naturally 
suggests itself, that the difference in the tint of the light 
seen is in some way dependent on the differing expansion 
or constriction of the two pupils, becomes inadmissible. 
Kew, January 30. E. Hwupparp. 
Use of the Kinematograph for Scientific Purposes. 
By means of the kinematograph it is possible to show 
to the eye the whole course of a visible phenomenon, either 
at the rate at which it actually happened or at any faster 
or slower rate that may be desired. 
Already it has been made use of to exhibit many pheno- 
mena the actual rate of happening of which is too rapid to 
admit of direct visual perception, as in the case of sound 
waves and the flight of bullets, but there would seem to be 
as great possibilities of useful application to render the 
progress of slow motions perceptible. For example, the 
changes in a cloudy sky are usually so gradual that it is 
difficult even for a close observer to form a definite mental 
picture of what has happened in the upper air during, say, 
a few minutes or a few hours. This difficulty is due not 
merely to the slowness of the changes, but to their com- 
plexity. But suppose that under favourable conditions a 
good cloud-scape could be photographed, say, 500 times in 
an hour, and the results put through a kinematograph in 
one minute, it could hardly fail to help the meteorologist 
to get a clearer idea of what really happens above us, 
especially as for purposes of study the same phenomenon 
could be made to pass betore the eyes of the student as 
often as he might desire. Perhaps our meteorological 
observatories may carry this method far. 
Again, suppose a similar application made to the growth 
or flowering of a plant. I imagine that few botanists have 
the patience and power of concentration that would be 
required to get as clear and definite an idea of such a 
process by direct observation as one could easily acquire 
by the aid of the kinematograph, and even supposing a 
botanist possessed a perfect mental grasp of the process, 
if he wished to describe it to an audience would he not find 
the kinematographic representation of it an invaluable aid ? 
No doubt many other possibilities will suggest themselves 
at once to the reader. Ro EME: 
