













































Marcu 24, 1923] 
warm soils, established a record in virulence. 
One may hope that the accumulation of such facts 
(of which the report contains many), and their 
correlation with the weather charts which are attached, 
will enable trustworthy forecasts of the intensity of 
particular diseases to be issued. It is unnecessary 
to emphasise the practical value of this to the grower. 
Another point of the highest practical interest, 
and one that is best brought out by the methodical 
records of a survey, is that of varietal resistance to 
ific diseases. Such a year as 1920 is invaluable 
in establishing the behaviour of different varieties 
of potatoes to blight under optimum conditions for 
the latter. Kerr’s Pink, for example, appears at or 
near the top of nearly all the lists of blight-resistant 
potatoes that are also immune to wart disease. 
Equally valuable are the records of new crop 
parasites. No less than 136 names have been added 
to this report as compared with that for 1919, and 
several of these are diseases not previously known to 
occur in the country. . 
The report deserves a wide circulation at home 
and abroad, as it presents in a handy and convenient 
form a remarkably complete summary of the fungous 
and allied troubles with which the British grower has 
to contend. 
Wave-power Transmission. 
AN interesting paper has recently been presented 
to the North-East Coast Institution of 
Engineers and Shipbuilders, by W. Dinwiddie, on 
Wave-power transmission. Wave-power machines 
e classified under three heads: (1) Continuous 
waves, where the generating plunger moves with 
imple harmonic motion. (2) Impulse waves, in 
hich a single harmonic motion is transmitted in 
ave form at regular intervals, greater than the 
period of the motion itself. (3) Sychronous and 
ychronous motors, monophase or polyphase, in 
which direction research is proceeding. 
Liquids such as oils and water are at present the 
media used, while the transmission of impulse along 
a steel wire has been used. A reciprocating pump 
plunger of small stroke is oscillated at a high speed at 
one end of a closed pipe line. Waves of compression 
and expansion are propagated through the pipe line. 
If the pipe line is completely closed at the other end, 
very high pressures can be generated in the pipe line ; 
but if a plunger similar to the pump plunger is placed 
there, this will move in synchronism with the pump 
plunger, and is therefore able to do work on some type 
of machine. To prevent excessive rise of pressure in 
the pipe line when the sychronising plunger is stopped, 
pacity analogous to a condenser in an electric 
circuit is put in the pipe line, and if all machines are 
ut off a stationary wave is formed and theoretically 
no energy is given to the system by the generator. 
It is desirable that connexions to machines along 
he pipe line shall be made at } wave-length points. 
achines ia in at half wave-length points along 
the pipe will be self-starting and stable in running, 
while those at the quarter wave-length and three- 
quarter wave-length will not be self-starting. If, 
however, a machine is started at half wave-length 
along the pipe, then a machine at a quarter wave- 
length will start; and if a machine is started at a 
wave-length along the pipe, then machines at a 
quarter and three-quarter wave-length will start. 
That this is so can be seen by examining the changes 
of pressure that take place at these points, when there 
a stationary wave, and when there is a progressive 
wave superimposed on the stationary wave. 
NO. 2786, VOL. 111] 
NATURE 
a disease that has recently been shown to prefer 
417 
The principle has been successfully applied to 
controls on aeroplanes, to the working of rock- 
drilling machines, and to riveters. A description 
of the special transmission pipes to resist the high 
pressures generated, and the mechanism for rotating 
the rock drill, is given in the paper. 


University and Educational Intelligence. 
ABERDEEN.—The University Court has agreed to 
refit the Botanical Museum in Old Aberdeen, prior 
to the occupation of the new botanical department 
which is at present being built there. It has also 
agreed to make provision for increased laboratory 
accommodation for the department of chemistry. 
CaMBRIDGE.—Mr. T. M. Cherry, Trinity College, 
has been elected to an Isaac Newton studentship, 
and the tenure of the studentship of Mr. W. M. H. 
Greaves, St. John’s College, has been renewed for 
one year. 
Smith’s prizes have been awarded to Mr. J. C. 
Burkill, Trinity College, for an essay on “‘ Functions 
of intervals and the problem of area,’ and to Mr. 
A. E. Ingham, Trinity College, for an essay on “‘ Mean 
value theorems in the theory of the Riemann Zeta- 
Function.” Rayleigh prizes have been awarded to 
Mr. E. F. Collingwood, Trinity College, for an essay 
on‘ The formal factorisation of an integral function 
of finite integral order,’ to Mr. W. R. Dean, Trinity 
College, for an essay on “ The elastic stability of a 
plane plate,’ to Mr. E. C. Francis, Peterhouse, for 
an essay on ‘“‘ The Denjoy-Stieltjes integral,’’ to 
Mr. C. G. F. James, Trinity College, for an essay on 
“The analytical representation of systems of space 
curves,’ and to Mr. M. H. A. Newman, St. John’s 
College, for an essay ‘‘ On discontinuities of functions 
of a single real variable.” 
The subject proposed for the Adams prize for the 
period 1923-4 is ‘‘ The physical state of matter at 
high temperatures.’’ Investigation is suggested of 
the statistical equilibrium of an assemblage of atoms 
in various ionised and quantised states together 
with free electrons and radiation. The essay may - 
deal, however, in any way with the simplifications 
or the complications which appear in the properties 
of matter at high temperatures. 
The Special Board for Oriental Studies will proceed 
to the election of the Eric Yarrow student in Assyrio- 
logy early next term. 
The Board of Research Studies in publishing its 
third report announces that the number of research 
students has risen to 179. Of these about two-thirds 
are working on the scientific side; chemistry and 
physics have the largest number, followed by botany, 
agriculture, and biochemistry. 
Grants from the Gordon Wigan fund have been 
made to Prof. Punnett for plant- breeding experi- 
ments, to the Museum of Zoology for cases, to Prof. 
Gardiner for a centrifuge and incubator, to Mr. 
Harker for sections of rocks, and to Prof. Seward 
for sections of fossil plants. 
DurHAM.—The council of Armstrong College, 
Newcastle-upon-Tyne, invite applications for the 
chair of philosophy. The latest date for the receipt 
of applications and testimonials is May 1. They 
should be sent to the Registrar. 
Lonpon.—The following doctorates have been 
conferred :—Ph.D. in Science: Mr. M. V. Gopala- 
swami of University College for a thesis entitled 
“Economy in Motor Learning” ; Mr. A. M. Moshar- 
rafa of King’s College for a thesis entitled ‘‘ The 
Quantum Theory of Spectral Series” ; Mr. W.S.G. P. 
