"The Japanese Current, Captain?"
"Certainly; that branch of it which breaks on the western shores of North America and then flows southeast towards the Isthmus of Panama."
"That may account for it, Captain," replied young Brownson; "at least, I hope it does, for then we may expect the valley to get shallower as we leave the land. So far, there's no sign of a Telegraphic Plateau in this quarter of the globe."
"Probably not, Brownson. How is the line now?"
"We have paid out 3500 fathoms already, Captain, but, judging from the rate the reel goes at, we are still some distance from bottom."
As he spoke, he pointed to a tall derrick temporarily rigged up at the stern of the vessel for the purpose of working the sounding apparatus, and surrounded by a group of busy men. Through a block pulley strongly lashed to the derrick, a stout cord of the best Italian hemp, wound off a large reel placed amidships, was now running rapidly and with a slight whirring noise.
"I hope it's not the 'cup-lead' you are using, Brownson?" said the Captain, after a few minutes observation.
"Oh no, Captain, certainly not," replied the Lieutenant. "It's only Brooke's apparatus that is of any use in such depths."
"Clever fellow that Brooke," observed the Captain; "served with him under Maury. His detachment of the weight is really the starting point for every new improvement in sounding gear. The English, the French, and even our own, are nothing but modifications of that fundamental principle. Exceedingly clever fellow!"
"Bottom!" sang out one of the men standing near the derrick and watching the operations.