234 Intelligence and Miscellaneous Articles. 



Prof. Ansted showed, by calculation, that even a vast increase in 

 the rainfall would not suffice to fill the valleys so as to deposit the 

 gravels as at present found. 



Mr. Whitaker quoted the existence of distinct terraces of gravel 

 one above the other in the Thames Valley as proving the gradual 

 excavation of the valley. 



Prof. Morris doubted as to the precise character and age of the 

 deposits in the valleys in South Wales having been accurately 

 ascertained. 



Mr. Tylor briefly replied. 



Prof. Ramsay made some concluding remarks, expressing his 

 disagreement with the views of the author as to the enormous 

 magnitude of the ancient rivers. 



XXXI. Intelligence and Miscellaneous Articles, 



ON THE PREPARATION OP CARBON TUBES, CRUCIBLES, ETC. 

 BY G. GORE*. 



HAVING had occasion to require small rods and vessels of carbon, 

 free (or nearly so) from silica, for experiments with hydrofluoric acid 

 and with fused fluorides, I have been induced to devise the following 

 method of obtaining them. Articles and vessels of the desired shape 

 (but of sufficient dimensions to allow for shrinkage) were formed of 

 different kinds of wood &c. ; they were then allowed to dry in a 

 warm place with occasional turning, then enclosed in a copper tube 

 retort provided with two exit-tubes for the escape of gas, the tube 

 placed horizontally between fire-bricks and heated with extreme 

 slowness at first, and finally to bright redness, by means of a row of 

 Bunsen's burners. It was necessary to continually turn the retort, 

 and so to distribute the heat during the burning-process that none of 

 the evolved tarry matter condensed upon the articles ; otherwise it 

 altered their form and dimensions in a remarkably curious and fan- 

 tastic manner. The red heat was continued until gas ceased to be 

 evolved. If the burning was too rapid, the articles fell to pieces or 

 cracked very much. 



The articles»formed by this process consisted chiefly of rods, cru- 

 cibles, boats, and tubes (the longest tubes made being 6| inches 

 long, after burning) ; and the materials experimentally employed 

 for their construction consisted of lignum vitse, boxwood, beech, 

 kingwood, ebony, ironwood, mahogany, zebra-wood, Memel oak, 

 English oak, rosewood, " bastard rosewood," maple, lancewood, 

 walnut wood, Norwegian pine, partridge-wood, " Braziletta," cocoa 

 wood, vegetable ivory (or taqua-nut), coquilla-nut, and the hard 

 shell of the cocoa-nut. The articles usually shrunk about one-fourth 

 of their original dimensions during the process ; but the amount of 

 shrinkage varied with the different kinds of wood &c. ; even with 

 the greatest care many of them became twisted and shapeless during 

 the process. 



The best kinds of these various materials were found to be lignum 



* Communicated by the Author. 



