destined to become the Royal Navy's Holland No. 1 was, it is thought, America's Holland Number 10 - known as the Adder Class. It was fitted with a 4hp Brayton petrol engine.
Working drawings supplied to Vickers had many discrepancies. and in some particulars were obviously incorrect. But building went on to these plans, and it was only after the boat almost turned on end during dock trials that Vickers were allowed to make modifications. The problems were due, in part, to the difficulties of communication with the Holland Boat Company, and the fact that construction of the RN Holland 1 was ahead of the prototype Adder Class and the drawings had therefore not been proved.
In the American design no periscope was fitted and the only way
