NAINI TAL LANDSLIP.—In NATURE, vol. xxii. p. 505, attention was directed to landslips in connection with the catastrophe at Naini Tal on September 18. We have just received part 4 of vol. xiii. of the Records of the Geological Survey of India, containing a paper by Mr. R. D. Oldham, of the staff of that Survey, who was deputed to examine and report on the landslip to the Director. From this paper and a note appended to it by Mr. Medlicott, it appears that we were in error in supposing Naini Tal to stand upon Tertiary rocks. It lies just to the north of the younger formations, and is situated upon “more or less imperfectly-cleaved clay slates.” These rocks are subject to a decomposition which penetrates deep into their mass, and it would seem to have been the cover of loose, decomposed detritus which, thoroughly saturated with water from the heavy rains, slid down the hill, and gave rise to the catastrophe.