Red Clay in the Ocean Depths 197 



globigerinas floating in it, which he thought must either 

 have subsided to this level while still living, or, after having 

 been born there, must be on their way to the surface, there 

 to live till they had reached full growth, when their increased 

 weight would cause them to sink. While agreeing with 

 Professor Thomson that the red clay was derived from the 

 foraminifera, he thought it a metamorphic form of the iron 

 alumina silicate, which often replaces, as in sundry green- 

 sands, the sarcode of the foraminifer after its death. In 

 Captain Spratt's dredgings from the Aegean he had found 

 particles of red clay among the glauconite grains, which 

 suggested by their shape that they had been formed in the 

 interior of chambers, which had afterwards been removed 

 by solution. 



Dr. Playfair called attention to some important Indian 

 coal-deposits, which had recently been found in the Nizam's 

 Dominions. Political considerations, which it was hoped 

 would be overcome, prevented English capitalists from 

 working them. Valuable deposits of iron ore also occurred 

 near some of them. 



1875. March i8th, 25ist meeting. Mr. Sylvester 

 exhibited a model of a new machine on the principle of 

 Capt. Peaucellier's parallel motion instrument (see page 192). 

 It had the form of a fan united at the ends by transverse 

 bars jointed in the middle. When the latter were straight, 

 the radii were equidistant ; when they were bent in alternate 

 directions, the angles formed by the radii are alternately 

 larger and smaller. This Vandyck fan, as he proposed to 

 call the instrument, could be easily applied to dividing an 

 angle into three parts, and Professor Clerk Maxwell had 

 suggested using the principle in constructing a spectrum 

 apparatus, for it ensured a regular angular movement of 

 the prisms. 



June lyth, 254th meeting. Sir J. Paget exhibited a 

 facsimile of a letter of William Harvey, lately found in the 

 British Museum. It was written from Flanders, where he 

 was travelling with the Duke of Lennox, and addressed to 

 Secretary Dorchester, to complain that his patent as King's 



