: May 15, 1873] 
NATURE 
49 
THE NEW PROFESSOR OF ENGINEERING 
AT GLASGOW 
ve has already been announced in NATURE that 
the Crown authorities have appointed Prof. James 
Thomson, C.E., LL.D., to succeed the late Prof. W. J. 
M. Rankine in the Glasgow Chair of Engineering 
and Mechanics ; and as that gentleman has been deemed 
worthy to occupy the Chair that was long filled by a man 
of world-wide eminence, it may not be undesirable to give 
a brief sketch of his professional and scientific career. 
Prof. Thomson is the elder brother of Sir William 
Thomson, and son of Dr. James Thomson, a former 
Professor of Mathematics in the University of Glasgow. 
The early part of his education was obtained in the Royal 
Belfast Academical Institution, and he completed his 
studies in Glasgow, where he obtained the degree of M.A. 
in 1840, with honourable distinction in Mathematics and 
Natural Philosophy. During the year 1841—42, he was a 
student in the class of Civil Engineering and Mechanics 
under Prof. Lewis D. B. Gordon, C.E., Rankine’s prede- 
cessor, and even then he was distinguished for his accu- 
rate mathematical and physical knowledge, and for his 
ready appreciation of the principles of applied mechanics. 
Heafterwards became an industrious pupil in the Horseley 
Iron Works and Manufactory, near Tipton, in South 
Staffordshire, and subsequently he entered the service of 
Mr. (now Sir) William Fairbairn, in whose workshops on 
the Isle of Dogs and in Manchester he had the benefit of 
assisting to execute engineering works of the greatest 
magnitude, and of great variety. After prosecuting his 
profession for several years in England and Scotland, he 
ultimately settled down in Belfast as a civil engineer. 
When the Professorship of Civil Engineering in Queen’s 
College, Belfast, became vacant in the year 1857, Mr. 
Thomson obtained the appointment. He has now occupied 
that position for a period of fifteen years. 
Besides attending to the duties of his class, Prof. 
Thomson carried on an extensive practice as a consulting 
engineer, both at home and abroad, chiefly in connection 
with water supply, irrigation, the drainage of sugar plan- 
tations in Demerara and Jamaica, and other swampy 
lands, and in designing machinery for the same, and in 
other hydraulic works. One of his earliest inventions was 
the well-known Vortex Turbine, which affords an admirable 
example of an unusual combination of great scientific 
knowledge and practical skill in the same person. This 
application of mechanical principles is one of the most 
successful means of turning water power to advantage 
that has hitherto been placed at the service of the engi- 
neering profession. Many examples of the Vortex Wheel 
are now in successful operation in various parts of the 
world, and the invention was deemed to be so important 
that the Privy Council renewed the patent when the 
ordinary period of fourteen years had expired. Another 
of his useful inventions is the Jet Pump and Intermittent 
Reservoir for the drainage of swampy lands. 
Among Prof. Thomson’s inquiries in the domain of 
pure physics a prominent place must be given to 
those which he instituted regarding the lowering of the 
freezing temperature of water hy pressure. This he 
determined by theoretical considerations entirely, and 
the result announced by Prof. James Thomson was after- 
wards exactly confirmed by the experiments instituted by 
his distinguished brother. The “arrival by theory with- 
out the aid of experiment at so extraordinary a physical 
fact, calls to my mind most forcibly,” says Joule, “the 
discovery of Neptune by Adams and Leverrier, and is 
one great step towards the position to which we may 
eventually hope science to attain, when a perfect ac- 
quaintance with theoretical principles will enable us to 
dispense with the appeal to experiment so necessary, in 
most cases, at the present time.” This discovery and its 
experimental verification immediately suggested a perfect 
solution of the problem of the descent of glaciers, and it 
has since led to many kindred discoveries in pure science, 
Like his predecessor, Prof, Thomson has extensively 
contributed to the advancement of science through the 
medium of the British Association. On five: separate 
occasions he has been selected as the Secretary of the 
Mechanical Section of that body, and he has beenanum- 
ber of times specially deputed to make reports and con- 
duct experimental researches for the solution of questions 
in practical engineering. The tendency of Prof. Thom- 
son’s mind may be, to some extent, judged of by the 
character of the papers on physical, mathematical, and 
mechanical subjects which he has published or commu- 
nicated to various scientific bodies. They are nearly forty 
in number, and are published in full or abstract in the 
Cambridge and Dublin Mathematical Fournal, the Edin- 
burgh New Philosophical Fournal, the Transactions of the 
Royal Societies of London and Edinburgh, the Proceed- 
ings of the British Association, and the Transactions of 
the Institution of Engineers in Scotland. 
Prof. Thomson’s honorary degree of LL.D, was ob- 
tained from the University of Glasgow about two years 
ago. His formal induction by the Senatus of the Uni- 
versity took place last month, and his professional duties 
in his ama mater will commence in the ensuing winter 
session. JOHN MAYER 
THE FERTILISATION OF THE WILD PANSY 
MONG the accurate and acute observations of C. C, 
Sprengel towards the close of last century,* which 
have received but scant attention from his successors, 
even down to our own day, was one on the subject of the 
colouring of variegated flowers. This botanist, with an 
insight into the mutual relationships of animal and vege- 
table life far in advance of his age, suggests that this 
colouring may serve as a guide to insects in seeking for 
the honey which serves for their food, and the search for 
which is so powerful an agent in the conveyance of the 
pollen, and the consequent fertilisation of the flower. 
Sprengel pointed out that in almost all variegated flowers 
the variegation follows a regular pattern, and that when 
it consists of streaks or stripes, these streaks almost in- 
variably point to the nectary, or the receptacle of the 
sweet secretions which form the food of insects, in what- 
ever part of the flower it may be situated. With this idea 
as a starting point, an interesting line of inquiry may be 
carried out as to the connection between the presence of 
scent and the absence of variegation in flowers. It will 
be found as a general rule, though not without exceptions 
—and it would be very interesting to attempt to trace the 
reason of these exceptions—that those flowers which pos- 
sess a powerful odour are (in the native state) self- or 
whole-coloured, while brilliantly variegated flowers are, 
as a rule, scentless, On the hypothesis that each of these 
properties has for its object the attraction to the flower 
of the insect necessary for the fertilisation of its seeds, it 
is easy to be seen that the presence of both in the same 
flower is needless ; and hence we find that Nature is in 
the habit of husbanding her resources, and not supplying 
needlessly to the same flower two different provisions for 
securing the same end. 
Having had an opportunity during the present spring of 
observing the structure, with reference to the phenomena of 
fertilisation, of the flower of the common Wild Pansy (Vola 
tricolor sub-sp. arvensis of Hooker’s “Student’s Flora”) 
I have thought a description of it might be of interest to 
the readers of NATURE, and especially to anyone who is 
able to contrast the phenomena in the variegated and 
scentless pansy with those in the scented and almost 
whole-coloured sweet violet. 
The corolla of the wild pansy consists of five petals 
* Das entdeckte Geheimniss der Natur im Bau und in der Pefruchtung 
der Blumen; von Christian Konrad Sprengel, Berlin, 1793. 
