JANuARY 7, 1904] 
NATURE 
223 
(1) A river is flowing at three miles an hour. If two 
steamers are ascending the river, making headway at the 
rate of three miles an hour, one propelled by the action of 
paddle wheels or a screw, and the other pulling itself up 
by means of a chain laid along the bed of a river, the former 
will have to exert twice the horse-power of the latter, 
although the resistance overcome and the distance travelled 
in any given time are the same in both cases. Why is this? 
(2) If a man is standing in an express train going at 
sixty miles an hour, he will have to perform exactly the 
same amount of work to throw a body of mass 1 lb. for- 
wards with a relative velocity of sixty miles an hour as if 
he threw it backwards with the same relative velocity. 
Yet in the former case the kinetic energy of the mass is 
increased from 121 to 484 foot pounds, while in the latter 
it is decreased from 121 foot pounds to zero. The actual 
work done by the man is in every case 121 foot pounds. 
This result has the appearance of being in contradiction 
with the principle of work. 
I have known many Cambridge lecturers who, when they 
attempted to solve problems of a similar character, arrived 
at very different results. I am able to account for the 
apparent contradictions of the principle of conservation of 
energy, although I did not learn to do so from text-books. 
The majority of readers of Nature are also, doubtless, com- 
petent to explain them in their own way and to their own 
satisfaction. But a student reared on the conventional text- 
book cannot fail to think (if he exercises his thinking powers 
at all on the subject) that the laws of dynamics must be at 
fault somewhere. G. H. Bryan. 
The Universities and Technical Education. 
HavinG just read Prof. Perry’s address on ‘‘ Oxford and 
Science,’’ I am tempted to give my own views on technical 
education for the Government service, and especially for the 
service of India, with which I have been connected since 
1869. My qualifications for this discussion are chiefly that 
I was Director of the Imperial Forest School at Dehra Dun, 
in India, for five years, and Deputy Director of that school 
for four years, and during those nine years I always in- 
structed the students personally in one of their branches of 
study. The excellence of the Dehra Dun Forest School has 
lately been recognised by the French Government, which has 
decided to send its Tonquin and Cochin China foresters 
there to complete their technical training, after having 
learned European forestry at Nancy. 
My experience in India has been that men who have taken 
university honours degrees in science make the best scien- 
tific Government servants, but need special training at a 
technical college to complete their education for the public 
service, just as candidates selected for the Indian Medical 
Service, after receiving a thorough European medical train- 
ing, complete their education at Netley. The Government 
of India fully recognises the advantages of a university 
training for its administrative and judicial service, 
commonly known as the Indian Civil Service, of which it 
is the most important branch, also for its Educational 
and Geological Departments, and the head of the Indian 
Meteorological Department always comes from a university. 
Why not also candidates for its Engineering and Forestry 
Departments? For these important departments, at pre- 
sent, boys are recruited chiefly from the public schools, where 
they may or may not have acquired the rudiments of scien- 
tific knowledge. Surely better candidates could be obtained 
if the age-limit were raised, and men trained in science and 
who have obtained an honours degree at a university were 
taught the technical part of their business at a well equipped 
Government college, such as the Royal Indian Engineering 
College, Coopers Hill. 
At present there is too much overlapping of studies at 
technical colleges, and immature students are hurried 
through their preliminary scientific studies and have not 
the necessary time to devote to subjects which will form 
their future life-work. The London medical schools are 
instances of this. With the best clinical instruction avail- 
able at the London hospitals, each of these institutions main- 
tains with difficulty a more or less complete staff to teach 
botany, physiology, &c., which should be taught at a central 
university. There would be a great saving of expenditure at 
technical colleges, and much greater efficiency, were the 
NO. 1784, VOL. 69] 
‘forestry. 
which is a necessary preliminary to 
technical knowledge acquired under the distinguished 
guidance of university professors. By passing through a 
university, candidates for the higher posts in the Govern- 
ment service would experience the excellent social atmo- 
sphere of the university by mixing with men who are fre- 
paring for all the different professions and positions in life, 
and would have a much broader training than is possible 
at a purely technical college, where there is always the 
danger of narrow views, and of the overcrowding of subjects 
of instruction. 
I hear that men who have taken a degree at Cambridge 
in the excellent mechanical school there are readily admitted 
without paying fees to complete their technical training in 
large engineering workshops, and surely a wider knowledge 
of engineering could be obtained at a Government college, 
such as Coopers Hill, than at any private engineering work- 
shop, where the work done must be of too special a character 
for Government service. The University of Cambridge does 
not contemplate being able to turn out finished engineers, but 
only men preliminarily trained for engineering, neither does 
it contemplate educating practical foresters, but merely men 
who have obtained a diploma in the theory of agriculture and 
There is a demand in the colonies, as well as in 
India and Egypt, and by some foreign countries, for 
English-speaking professors of engineering and forestry, as 
well as for trained engineers and foresters, and at present 
the supply of such men is quite inadequate, and frequently 
these appointments are given to foreigners, simply because 
properly trained men from our country are not available. 
Forestry can be admirably taught at Coopers Hill, with 
14,000 acres of the Windsor Forest at our doors, and with 
examples of forests at Alice Holt Wood, in the Chiltern 
Hills, and elsewhere, easily accessible by train. The splendid 
forests of the north of France are within a day’s journey, 
while, after a six months’ practical training in the German 
forests, no forester in the world can be better equipped than 
are our students. Were our first year students university 
men instead of schoolboys, America and the colonies would 
be tempted to send us more students, and one of the finest 
technical colleges in the world might be easily established. 
Coopers Hill, January 1. W. R. FIsuer. 
scientific education 
Prof. Johannsen on Heredity. 
I sHouLp be glad if you would allow me space for some 
remarks on two recent reviews of Prof. Johannsen’s 
‘‘Erblichkeit in Populationen,’? in the last issues of 
Biometrika and of Nature (December 17) respectively, the 
former signed by Prof. Pearson and Prof. Weldon. 
I find it difficult to understand Prof. Johannsen’s book in 
the sense in which the reviewers have, apparently, read it. 
In both notices it is stated that, if the author’s views were 
correct, the correlation between mother and daughter plants 
should be perfect. As I take it, however, Prof. Johannsen’s 
view does not imply, and is not consistent with, such a 
hypothesis; he believes, and adduces evidence to show, that 
within the pure line ‘‘ Der Riickschlag ist vollkommen, 
ganz bis zum Typus der Linie,”’ and explains the result on 
the hypothesis that the germ-plasm structure (or whatever 
we may term it) for the pure line is constant, the variations 
purely somatic. Neither the existence of zero correlation 
between parent and offspring nor the assumed somatic 
character of variations, within the pure line, is consistent 
with perfect correlation between parent and offspring for the 
race at large. This misunderstanding, in my view, is 
fundamental. 
With reference to the concluding paragraph of the review 
in Nature, it may be pointed out that Prof. Johannsen 
undertook the definite task, clearly stated, of elucidating the 
nature of intra-racial heredity by the study of heredity within 
the pure line, i.e. the offspring of one self-fertilised in- 
dividual. He has shown that the intensity of heredity 
between the first two generations sprung from such a single 
individual may be vanishingly small, although it is quite 
sensible within the race at large. The result is of great 
importance both as regards the theory of heredity and the 
practice of breeding, and the work cannot be termed in any 
sense a failure. 
One would, certainly, wish that Prof. Johannsen had 
employed more advanced statistical methods, and one may 
