198 - REPOiiT— 1897. 



the mouth of the Congo, extending seawards, there is a difficult gully 

 to cross, the walls of which are 2,000 feet in height ! Although the gully- 

 widens towards the west, this height is maintained for a considerable 

 distance. The shallowest water is found along the edges of this gully, 

 which therefore has a transverse section not unlike that of a river bounded 

 by a naturally formed levee. 



The East Coast of Africa. — The following are interruptions noted in 

 various cable sections along the east coast of Africa : — 



Mozambique — Zanzibar. — February 1, 1885 ; April 2, 1885 ; September 2G, 1894*. 



Delaqoa Bay — Durban. — October 15, 1890; November 18, 1890; December 10, 

 1894 ; January 20, 1896* ; July 13, 1896*. 



Mozambique — Delagoa Bay {Lorenzo Marquez). — November 11, 1890 ; November 

 18. 1890; January 5, 1893*; January 25, 1893*; June 9, 1895*; December 24, 

 1896.* 



Zanzibar — Mombasa. — December 20, 1890 ; January 25, 1892 ; September 4, 

 1894*; September 26, 1894*; March 6, 1896*; August 23, 1896*; September 

 23, 1896*. 



Aden — Zanzibar. — January 8, 1890^ May 11, 1891 ; December 5, 1891 ; February 

 20, 1893*; August 9, 1893* ; December 21, 1894; September 2, 1895*; December 

 24, 1895* ; January 27, 1896* ; March 16, 1896* ; March 23, 1897 (?).* 



With the nineteen interruptions marked with an asterisk, there are 

 eleven instances where these may have corresponded with the records of 

 unfelt earthquakes. Approximate coincidences with earth- movements 

 are as follows : — 



January 22, 1893, at 19'87h. A weak disturbance was noted at Nicolaiew and 

 Strassburg. 



September 1, 1894, from Ih. 43m. to 4h. 21m. Moderate at Charkow. 



September 25, 1894, 16h. 49m. to 17h. 8m. At Charkow. 



February 20, 1893, from 19-23h. to 19-78h. At Strassburg small, origin in Japan. 



August 9, 1893, from 17h. 11m. to 191i. 4m. At Strassburg moderate. 



March 3, 1896, at 16h. 33m. Recorded through Europe. 



August 21, 1896, at lOh. Om. Recorded at Padua. 



September 2, 1895, at l-3h. to 9-6h. and 19h. At Shide. 



March 15, 1896, at 19h. 36m. At Shide. 



September 21, 1896, at 16h. 63m. Recorded through Europe. 



March 23, 1897. At Sliide at 4-29h., slight. 



Sir James Anderson, in 1887, speaking about the interruptions off 

 the river Rovuma (11° S. lat.), remarks that, so far as soundings showed, 

 there was an even bottom and all that could be desired as a bed on which 

 to place a cable, yet every year the cable broke. The broken ends 

 suggested that the cable had been suspended until it snapped. Although 

 the cable was shifted further out, and then closer in, it still broke. This 

 happened eight times, and it was noticed that the interruptions occurred 

 at about the same time of the year. Seven of these breaks are fairly on 

 the same line, and Sir James's suggested explanation of this cause was 

 that the time when the interruptions occur is at the termination of 

 the rainy season in the African mountains, at Avhich time fresh-water 

 springs take away the bottom on which the cable lies, and leave it 

 suspended. 



Mr. John Y. Buchanan suggests that sometimes a cable may be 

 broken in consequence of its slowly subsiding through ooze, until the 

 catenary strain becomes so great that it eventually snaps. 



Aden — Bombay. — Interruptions noted on this section were the 

 following : — 



July 11, 1881 ; June 3, 1885 ; July 27, 1885 ; July 11 1888 August 11, 1888. 



