4 04 London Electrical Society. 



minute and careful observation of the nature of the individual strata, 

 and a scientific application of subterranean drains at the contact of 

 each permeable stratum with a subjacent bed of clay. 



Tunnels can be safely formed without masonry in unstratified 

 rocks of hard granite, porphyry, trap, &c, and in compact slate 

 rocks ; also in masses of tufa, such as cover Herculaneum, and are 

 pierced by the grotto of Pausilippo near Naples ; but, in his opinion, 

 wide tunnels driven in stratified rock could not be considered secure 

 unless they were supported by arches. 



Mr. Sopwith confirmed the remarks on the importance to the 

 civil engineer of a knowledge of the geological character of the strata 

 through which tunnels or open cuttings were to be made : the cost 

 was materially affected, as well as the stability of the works. The 

 angle of inclination and the lines of cleavage should be carefully 

 studied : on one side of a cutting the slope might be left steep, and 

 all would be firm and dry ; whilst on the other, if the same slope 

 was adopted, all would appear disintegrated and wet, and a series of 

 accidents would be the necessary consequence. He could not suffi- 

 ciently urge the importance of a more intimate connexion between 

 the geologist and the engineer. 



LONDON ELECTRICAL SOCIETY. 

 [Continued from p. 313.] 



Oct. 18, 1842. — The Chairman announced that Walter Hawkins, 

 Esq., M.E.S., F.Z.S., &c, had presented the Society with a third spe- 

 cimen of the Gymnotus Electricus ; but which, like the two former, 

 has not survived the voyage. It is now undergoing dissection, the re- 

 sult of which will be laid before the Society. Mr. Hawkins intends 

 persevering until he succeeds in his desire to present a living speci- 

 men to the Society. 



A letter to the Secretary from Mr. Phillips, M.E.S., was read, con- 

 taining " the particulars of a fatal accident by lightning at S e - Blazey ." 

 Some children had taken refuge from a storm in a toll-house, near 

 which was an elevated crane, and also a comparatively lofty house. The 

 electric matter discharged itself, not on either of these (apparently) 

 better objects, but burst upon the low hut, and in its passage to the 

 earth killed two of the children, and hurt others. From the draw- 

 ing which accompanied this letter, it appears that the toll-house was 

 immediately at the edge of a rivulet. The lightning divided itself 

 in its passage down the house, first entering by the soot of the 

 chimney. The letter also contains an account of the damage done 

 to a ship at Par by the same storm. The top-mast was shattered to 

 pieces ; a large piece was knocked out of the lower part of the main- 

 mast ; the rupture occurred exactly at the termination of a chain 

 hanging from the cross-trees, the said chain having protected the 

 upper portion of the same mast. Several men were knocked down. 

 The crew spoke of a suffocating smell of sulphur. 



A translation, by Mr. "Walker, Hon. Sec, of M. Becquerel's first 

 observation " On the Electro-Chemical Properties of Simple Bodies, 

 and on their application to the Arts," was then read. The author 



