ii Proceedings. \October 21st, igu2. 



Ordinary Meeting, October 21st, 1902. 



Charles Bailey, M.Sc, F.L.S., President, in the Chair. 



The thanks of the members were voted to the donors of the 

 books upon the table. 



Mr. Thomas Thorp, F.R.A.S., stated that he had recently 

 demonstrated the explosive property of celluloid in a striking 

 manner. He withdrew the cordite from a small ball cartridge, 

 replaced it with powdered celluloid, and with this charge fired 

 the bullet through a board one inch in thickness. 



Mr. C. E. Stromever, M.Inst.CE., read the following 

 communication on "The Growth of Miniature Volcanoes 

 in Boiler Scale," and exhibited several specimens of scale. 



The samples of boiler scale which are shewn this evening 

 are of rare occurrence, and resemble, as will be seen, miniature 

 volcanoes, their growth being I think very similar to the growth 

 of real volcanoes, except that, instead of the added matter around 

 the vents being thrown up as dust and lava, it is extracted from 

 the boiler water in which it was held in solution. Probably the 

 raising of the land around mineral springs is the exact counterpart 

 of the growth of these vents in boiler scale. 



Mr. Yarrow once made an experiment on circulation by 

 suspending a U tube from a reservoir filled with water. Having 

 heated, say, the right leg until circulation was set up, the circula- 

 tion was not reversed when tlie flame was transferred to the left 

 leg. If, therefore, good circulation by heating is once established, 

 these conditions would have to change considerably before the 

 current of steam and water is reversed. 



In the case of hot springs, surface water enters into a porous 

 stratum, and under favourable conditions descends to a depth 

 where it acquires a considerable temperature. Should there be 

 openings here to the surface, this warm water will rise and over- 

 flow, carrying with it soluble and even insoluble matter, which 



