1856 - began laying submarine cable; subsequently became chief engineer at the Telegraph Construction and Maintenance Company in Greenwich; participated in cable laying voyages of SS 'Great Eastern'
1878 - invented wire-sounding machine which was first used on the cable laying ship the 'Alert';
1887 - invented type of oceanographic sounding machine;
1891 - patented scoop sounder, an instrument also known as the 'snapper' it was used when cable laying
Francis was employed by the English Telegraph Construction and Maintenance Company