All About Inventions and Discoveries
The Romance of modern scientific and mechanical Achievements

76 All About Inventions easily and readily, and came awash without the slightest hesitation when desired. She moved under- water and answered her helm. The one-man crew within related that when submerged he experienced no difficulty in breathing, and that the supply of air from the compressed air reservoirs worked satis- factorily. This vessel was considered to be so promising that it was decided to push ahead without delay with a second, improved and larger, craft. The defects which had been manifest in the first vessel were capable of elimination. To ensure this second craft being completely satisfactory, an arrangement was consummated whereby Holland relinquished his school duties to devote his sole energies to the build- ing of the new boat, the secret fund being drawn upon to reimburse him for his loss of salary as a teacher. The submarine was duly completed, and it proved a decided advance upon its predecessor. There was accommodation for a crew of two, Holland himself taking the helm while his assistant served as engineer during the trials. The boat followed the Fulton principle of design and operation, vertical and hori- zontal rudders serving as the control. The boat aroused distinct interest owing to the facility with which she submerged and rose to the surface. This vessel virtually ushered in the diving principle which is the outstanding characteristic of the submarines of to-day. Hitherto the practice was to sink and to rise upon an even keel, the disadvantage of which was the time occupied in submerging. With this little craft Holland performed various evolutions in the waters washing New York City,