of Edinburgh, Session 1884-85. 
311 
Monday , 20 th July 1885. 
DAVID MILNE-HOME, Esq., LL.D., Vice-President, 
in the Chair. 
The following Communications were read : — 
1. On Patella. Part II. By Dr Harvey Gibson. 
2. On the Unifilar Knots with Ten Crossings. By the Kev. 
T. P. Kirkman, F.R.S.* Communicated by Professor Tait. 
3. Census of Ten-fold Knottiness. By Professor Tait. 
4. On the Thermal Effects produced, in Solids and in Liquids, 
by sudden large Changes of Pressure. By Messrs H. 
G. Creelman, B.A., and J. Crocket. Communicated by 
Professor Tait. 
In several papers communicated to the Society within recent 
years the thermal effect of compressing water has been dealt with 
by various observers. The present paper gives the results of ex- 
periments of a similar kind to ascertain the thermal effects of com- 
pressing certain solids and liquids. These experiments were con- 
ducted in the University of Edinburgh, under the superintendence 
of Professor Tait. 
Pressure was applied by forcing water by means of a powerful 
force pump into a strong steel tube, called the “small gun” (shown 
in section in the accompanying figure). Within this, a thermo- 
electric junction of nickel and iron wires was placed, most of the 
wire within the gun being in the form of a coil, so that the junction 
could be drawn up and pushed down as required. The wires passed 
out of the gun between two well-oiled leather discs, which could be 
tightly screwed together between a steel plate and a similar one 
forming the lower part of the gun. The nickel wire formed, with 
an iron wire, another junction, called the “ outer junction,” which 
was kept in water at a uniform temperature. The two iron wires 
were connected with a Thomson’s dead-beat galvanometer (resistance 
* A Supplement to this paper will be printed after the Proceedings for 
July 20. 
