Most of these vessels were torpedoed by German submarines, although in some cases it has not been established whether the damage was inflicted by mines or underwater boats.

They have been found upto a height of 23,000 feet up Mount Everest as well as underwater.

Grand Fleet submarines were used in the northern areas during 1916, and Harwich submarines operated farther south, but the number of underwater craft available was insufficient for any extended method of attack.

It was only on rare occasions that it was possible to bring off a successful attack on a submarine that had been sighted, the low underwater speed of submarines making it difficult to get into position when the enemy was only sighted at short range, which was naturally usually the case.

The otter could not escape now, since the hounds would watch the underwater entrance to the cave among the alder roots, while the terrier would crawl down from the other side.

While swimming underwater she collided with a middle-sized sea-serpent, which was evidently in difficulties and made its way to the beach, where it expired.

With its help he even managed to secure a foothold on the narrow one-brick ledge which terminated the deep underwater wall of the reservoir.

The underwater zoo.

Diving, cutting & welding in underwater salvage operations.

Underwater fight.

R611338. Underwater explosions.

Underwater operation.

The underwater zoo.

Diving, cutting & welding in underwater salvage operations.

Underwater fight.

R611338. Underwater explosions.

Underwater operation.

Evidently she was indulging in one of her underwater tricks.

It seemed to him that there should be some way of communicating through the water and of listening for sounds underwater.

Thus the idea of underwater signaling was born.

VIII TELEGRAPHING BENEATH THE SEA Early Efforts at Underwater TelegraphyCable Construction and ExperimentationThe First CablesThe Atlantic Cable ProjectedCyrus W. Field Becomes InterestedOrganizes Atlantic Telegraph CompanyProfessor Thomson as Scientific AdviserHis Early Life and Attainments.