It was not necessary to spend many minutes in order to learn if the machinery was in working order. When Sidney applied the spark which ignites the gas, the screw immediately began to revolve, and he had no difficulty in sending her ahead or astern at will.
"I reckon there's no great need of your spendin' very much time over that end of the business," the keeper said in a tone of satisfaction. "You an' Sammy had better give the engine a thorough cleanin', an' when that has been done I'll try to answer the questions you asked this mornin' about the light, if you come up into the lantern."
Then Captain Eph went back to the tower, and when the two were busily engaged obeying orders, Mr. Peters asked curiously:
"What did the cap'n mean, Sonny, about answerin' your questions?"
"I wanted to know about the lens," Sidney replied. "I can't understand why it is any better to have all those glass rings around the light, which make so much work for the cleaners, than it would be if it was one solid globe."
"So Cap'n Eph thinks he can explain all that, does he?" Mr. Peters said with a queer gurgle in his throat, much as if he were choking. "Wa'al, all I can say is, if he does, it'll be a good deal more'n I've ever heard of his doin' yet. He'll spin a lot of stuff 'bout bendin' the rays, an' after he gets through you won't know quite as much as you did before."
Because he did not understand the meaning of Mr. Peters' remark, Sidney remained silent, and shortly after, the motor having been cleaned thoroughly, he went into the lantern, where he found the keeper awaiting him.
Captain Eph had before him several open books, as if he had been refreshing his memory on the subject of lenses, and immediately Sidney appeared, he said, in an apologetic tone:
"I don't count on bein' able to give you the idee as to the work of the lenses sich as a man ought'er; but I'll try my best, an' if I fail you won't be any worse off than you are now. In the first place this 'ere is what is known as a light of the first order, meanin' the most powerful in the service, an' the lens alone cost about eight thousand dollars. The middle part of the lens is made up of what's known as 'refractors,' which, 'cordin' to my way of tellin' it, are rings of glass makin' a hollow cylinder six feet in diameter, an' thirty inches high. Below it, as is printed here," and Captain Eph pointed with his thumb to one of the open books, "are six triangular rings of glass, ranged in a cylindrical form, an' above it, a crown of thirteen rings of glass, formin' by their union a hollow cage composed of polished glass, ten feet high, an' six feet in diameter, like this 'ere," and Captain Eph waved his hand toward the brilliant apparatus before them, a picture of which is given here.