348 
Proceedings of Royal Society of Edinburgh, [may 21, 
of the basalt plateaux, it serves as a striking memorial of the pro- 
longed duration of the volcanic period, and of the enormous denuda- 
tion which the Tertiary volcanic rocks of the British Isles have 
undergone. 
• In the last section a brief summary is given of the general suc- 
cession of events, of which the detailed evidence is presented in the 
previous parts of the paper 
Monday, 4dh June 1888. 
Dr JOHN MUEEAY, Vice-President, in the Chair. 
1. Exhibition of Photographs. 
Dr G. Sims Woodhead exhibited a series of Photographs of Large 
Sections of the Lung. 
The following Communications were read : — ■ 
2. Mean Scottish Meteorology for the last Thirty-two 
Years, discussed for Annual Cycles, as well as 
Supra-annual Solar Influences, on the basis of the 
Observations of the Scottish Meteorological Society, 
as furnished to, and published by, the Registrar- 
General of Births, Deaths, &c., in Scotland, after 
being computed for that Office at the Royal Obser- 
vatory, Edinburgh. By the Astronomer-Royal for 
Scotland. 
3. On John Leslie’s Computation of the Ratio of the 
Diameter of a Circle to its Circumference. By 
Edward Sang, LL.D. 
Of all the processes for computing to great precision this most 
important ratio, that by means of the series for the arc in terms of 
its tangent is the most rapid. Seemingly short, however, it is truly 
a very long process ; to reach its beginning we must know the laws 
of differentials and integrals, must he familiar with the higher 
