This title has been chosen to define precisely the scope of the paper. No industrial enterprise exacts of its votaries from inception to completion, wider and more thorough knowledge of their respective specialties, than does the uniting of distant countries by telegraph cable. The statistician, hydrographer, physicist, manufacturer and seaman must all do their utmost possible to avert from the project the disaster that any miscalculation, careless reconnaissance, clumsy workmanship, or inadequate equipment will loudly invite. So much is comprehended in the phrase Submarine Telegraph Work, that in a limited article it will be impossible to dispose of more than a single branch of the subject, with any degree of completeness. To elect this branch is then the question, and, considering each in turn, the choice naturally falls on that of which least has hitherto been said.