56 Royal Societi/ : — 



nearer the circumference of the vitreous body than its centre — con- 

 sisls of comparatively large ones. 



" Whenever the eye i^otates, this filamentous peripheral system 

 will in its relative (counter) rotation, gradually, though soon, come to 

 the end of its tether, and in this interval and when there, act as a 

 check upon the relatively rotating fluid ; jjcrpetually reiterating ob- 

 struction, above all in the immediate vicinity of the capsule and (by 

 the disposition of the threads to float vertically) most eff^ectually in 

 the most important or horizontal direction. The middle of the 

 vitreous body being free of impediment, relative rotation of the fluid 

 expends itself there, whilst a practical concurrence in the ocular ro- 

 tation ensues near the capsule. And thus in the incessant move- 

 ments of the eye, head and body, the wall that confines the fluid can 

 sufi^er no severe concussions from eddies in the latter. In other 

 words, we have herein a provision that the crystalline lens may not 

 be shaken, the circulation in the retinal vessels may not be deranged, 

 and sensations of light may not be ever assailing us from impulses 

 ot the vitreous fluid, perhaps that the retina may not itself suflfer 

 direct injury therefrom." 



" An Account of some Experiments made with the Submarine 

 Cal^le of the Mediterranean Electric Telegraph." By Charles Wheat- 

 stone. F.R.S. 



The following results were obtained between May 24 and June 8 

 in last year, with the telegraphic cable manufactured by Messrs. 

 Kuper and Co. of East Greenwich, for the purpose of being laid 

 across the Mediterranean sea, from Spezia on the coast of Italy to 

 the island of Corsica. The manufacturers, in conjunction with 

 Mr. Thomson the engineer of the undertaking, kindly aff"orded me 

 every facility in carrying on the experiments. The short time that 

 elapsed between the opportunity presenting itself and the shipping 

 of the cable for its destination, prevented me from determining with 

 sufficient accuracy some points of importance, respecting which I 

 was only able to make preliminary experiments, but the following, 

 which I Mas able to eflect with the means at hand, may possess 

 suflicient interest to be made public. They present perhaps nothing 

 theoretically new, but I am not aware that experimental verifications 

 of some of these points have been made before. I assume that the 

 reader is acquainted with the experiments of Dr. Faraday described 

 in the Philosophical Magazine, Ser. 4, vol. vii. p. 197. 



The cable was 1 10 miles in length, and contained six coj)per wires, 

 one-sixteenth of an inch in diameter, each separately insulated in 

 a covering of gutta percha one- tenth of an inch in thickness. The 

 whole was surrounded by twelve thick iron wires twisted spirally 

 around it, forming a complete metallic envelope one-third of an inch 

 in thickness. A section of the cable presented the six wires arranged 

 in a circle of half an inch diameter, and one-fifth of an inch from the 

 internal stirface of the iron envelope. 



'ilie cable was coiled in a dry well in the yard, and one of its ends 

 was brought into the manufactory. The wires were numbered 1, 

 2, 3, 4, 5, 6, and the ends in the well were indicated by an accent ; 



