178 PHTSICAL GEOLOGY. 



Roberts, W. C. On the Columnar Form of Basalt. Rep. Brit, Assoc. 

 for 1874, Sections, pp. 91,92 ; Coll. Guard, vol. xxviii. p. 392 (1874). 

 Describes experiments on the effect of heat on bricks. When heated 

 to redness they contract from 3 to 4 p. c. ; and the unequal strain 

 attending this pro'duces a columnar structure, much like that of certain 

 basalts. W. T. 



Roth, J. TJeber die neue Theorie des Yulkanismus des Herrn R. 

 Mallet. [On Mallet's new Theory of Vulcanism.] Zeitsch. deutsch. 

 geol. Ges. Heft iii. pp. 550-573. 

 A critical examination of Mallet's paper in the Phil. Trans. .Brings 

 forward numerous objections to the theory, which he regards as insuf- 

 ficient and unnecessary. F. W. R. 

 Schmidt, Dr. J. F. J. Studien iiber Erdbeben. [Studies on Earth- 



qnakes.] 330 pp., 6 plates. Leipzig. 

 Schott, Ch. A. On Underground Temperature. Ann. Bep. Smith- 

 son. Inst, for 1874, pp. 2^9-253. 

 Brief resume of the present state of inquiry on the subject. Gives 

 results of experiments at Brussels, Edinburgh, and Chicago. Quotes 

 largely from Prof. J. D. Everett's paper [see Geological Recokd for 

 1874, p. 163], and concludes with a short list of authorities to be con- 

 sulted. G. A. L. 

 Scrope, Gr. P. 'Notes on the Volcanic Eruptions of Iceland. Geol. 



Mag. dec. ii. vol. ii. pp. 289-291. 

 Reprints (from the Scotsman of May 21) an account of an eruption, 

 comments on the facts stated, and gives a summary of the phenomena. 

 One eruption is said to have produced no ashes : this statement Mr. 

 Scrope regards as incorrect ; he believes that the ashes were carried by 

 the wind away from the observers. Ashes of some of the eruptions 

 were carried as far as Sweden. W. T. 



. Cup-shaped joints in Basalt. Nature, vol. xiii. p. 47. 



In reply to Mr. Mallet, states that one of the three columns in the 

 hall of the Geol. Soc. exhibits an articulation in the shape of a double- 

 concave lens. The articulation is 3 or 4 inches thick, and shows no 

 evidence of a plane of separation, as suggested by Mr. Mallet. C. E. De R. 

 Shaler, N. S. Notes on some of the Phenomena of Elevation and 

 Subsidence of the Continents. Proc. Boston Nat. Hist. Soc. vol. 

 xvii. pp. 288-292. 

 Believes that some amount of the apparent elevation and depression 

 of the land is due to absolute change of sea-level. The following causes 

 might produce such change : — movements of the sea-floor ; accumula- 

 tions on the sea-bottom ; abstraction of water to form ice-sheets ; change 

 in position of the fulcrum-line of oscillations of level; transfer of 

 weight to the land by the accumulation of an ice-sheet. F. D. 



. Recent Changes of Level on the Coast of Maine, with reference 



to their origin and relation to other similar changes. Mem. Bost. 

 Soc. Nat. Hist. vol. ii. pp. 322-341. 



