The Boy With the U. S. Life-Savers Part 7

"Well, my boy," the other said, "I'll take a little credit for that.

Don't forget I was your first swimming teacher! But I couldn't do all those things you've been telling me about, now. I'm glad to know they've got as high a standard as that in the Volunteer Corps. I shouldn't wonder if the Coast Guard would be able to get some of its best men from the volunteer ranks. Take yourself, for example."

"It's done me a lot of good," said the boy.

"Of course it has. It would do anybody good. But I've been wanting to ask you, Eric, what effect the formation of this new Coast Guard will have on your plans?"

"It won't hurt them a bit," the boy answered. "I wrote to the Captain Commandant about it and he sent me the dandiest letter! I'll show it to you when my trunk gets home. You see, Father, when the Life-Saving Service and the Revenue Cutter Service joined together under the name of the Coast Guard, it was arranged that every member of both services might reenlist without examination. And my application was in last year.

So that there's nothing special, I'm just going through the regular order of things. That is, if I can make the Coast Guard Academy."

"You ought to manage it, I think," said his father. "I'm really glad you have made up your mind to it, Eric," he continued; "it's a good full-size man's job. And you have quite a bit of the salt in your veins, my lad, for, after all, most of your kin are seafaring folk."

"You never had anything to do with the old Revenue Cutter Service, had you, Father?"

"I was never a member of it," the other replied, "but I've seen it at work, many times these forty years. No, I got into the Lighthouse Service when I was about your age and I've given every bit of myself to it ever since. I'm glad I did. I think the last fifty years has shown the greatest development of safety at sea since the days of the discovery of the compa.s.s."

"Yet you didn't want me to join!"

"Not now," the old inspector answered. "Conditions have changed. The Lighthouse Service of to-day is a complete and perfected organization.

Every mile of United States territory is covered by a beacon light. We were pioneers."

"I see," said the boy thoughtfully.

"It's a good deal the same sort of development that's struck the cattle country," the Westerner said, meditatively. "When I was a youngster, a cattle-puncher was really the wild and woolly broncho-buster that you read about in books. In the days of the old Jones and Plummer trail, when there wasn't a foot of barbed wire west of the Mississippi, a cowboy's life was adventurous enough. A round-up gang might meet a bunch of hostile Indians 'most any time, and a man had to ride hard and shoot straight. But now the ranges are all divided up and fenced in. The range-runner has given way to the stock-raiser. It's like comparing Dan'l Boone to a commercial traveler!"

"I don't quite see how that fits the Lighthouse Service," said Eric, smiling at the Daniel Boone comparison.

"Well, it does to a certain extent. When I first went into the Service, half the coast wasn't protected at all. And even the important lights we had were weak, compared with what we have now. Why, Eric, we've got lights so powerful now that we can't even tell how strong they are!"

The boy looked up incredulously.

"It's an absolute fact," the old inspector continued. "The most powerful light we have is on Navesink Highlands, near the entrance of New York Harbor. It's reckoned at between two million and ten million candle-power. n.o.body's been able to measure it. The United States Bureau of Standards was going to do it, but so far, they've left it severely alone."

"How far can that be seen, Father?"

"All depends on the height of the ship's deck from the water," was the reply. "The curvature of the earth determines that. Say, thirty miles on a vessel of moderate size. But the reflection of the Navesink Light on the sky has been seen as far away as eighty miles."

"White light?"

"Yes, white flashing," was the reply.

"I've noticed," the boy said thoughtfully, "that red is only used for the smaller lights. I wanted to ask you about that the other day. Now there's Point Adams Light," he continued, pointing off the starboard bow as the lighthouse-tender steamed out of the mouth of the Columbia River, "it looks just as big as this light on the other side, on Cape Disappointment, but it's a lot harder to see. When I've been headed for home, on a misty night, after a day's fishing, I've missed Point Adams when Cape Disappointment was as clear as could be."

"But you could see other lights?"

"Oh, yes, there wasn't any difficulty in making the harbor, either in or out. I was just wondering whether the color of the light had anything to do with making it seem dim?"

"Of course," his father answered; "a red gla.s.s cuts off sixty per cent, of the light. You can't see the Point Adams Light for more than about eleven miles, but, in ordinarily clear weather, you can see the fixed white light of Cape Disappointment for all of twenty-two nautical miles."

"I don't quite see why," said the boy, puzzled.

"That's because you're not taking the trouble to think," was the impatient reply. "You know that light is made up of all the colors of the rainbow?"

"Of course."

"And red is only a small part of that, isn't it?"

"Yes."

"Well, don't you see? Red gla.s.s only lets the red rays through and cuts off all the rest. How could it help being a lot fainter? And, what's more, red doesn't excite the nerves of the eye as much as white does, so that if there were two lights of equal power, one red and one white, the red would be less easily seen."

"Why do the railroads use red for danger signals, then?"

"Habit, mainly. It's wrong, of course, and a good many of the railroads are changing their danger signals from red to yellow. So far as we're concerned in the Lighthouse Service, however, we're getting rid of all the fixed red lights wherever a long-range warning is needed."

"How do you distinguish the different lights, then?"

"Using flashing lights, with flashes of different duration."

"Why didn't you always do that?" asked Eric.

"Didn't know enough," was the simple reply. "It's only lately that we've found out how to work a flashing light without any loss of power.

In the old days we used to depend on occulting lights, but now, flashing lights are much more powerful. You know the difference?"

"Sure! An occulting light means that some of the time the light is shut off, and at others it isn't. Wasn't it worked by a revolving shutter with wide slits in it?"

"That was the old idea. We use it still as a cheap way of changing a fixed light to one with a definite character. It works all right, only it's a waste of power to have the light darkened part of the time. Then, too, if the shutter revolves too quickly, the light is like little flashes of lightning, while, if it goes too slowly, a lookout might happen to scan that point on the horizon at the instant it was dark. In that way the value of the warning would be lessened."

"I know the flashing light is quite different, Father, but just how is it worked?" asked the boy. "It's because of some arrangement of the lens, isn't it?"

"Exactly. Light travels in straight lines in every direction. One of the problems of illumination in lighthouse work is to make all these beams come to one focus. We don't want to light the sky, nor the sea at the foot of the lighthouse. So a first-order light is built up of rows on rows of prisms so arranged that the light will be refracted from every direction to one point. An ordinary student's reading lamp, inside a big lighthouse lens, would give a light that could be seen a good many miles!"

[Ill.u.s.tration: REFILLING PINTSCH GAS BUOY.

Courtesy of Safety Car Lighting Co.]

[Ill.u.s.tration: LIGHTHOUSE TENDER APPROACHING BUOY.

Courtesy of Safety Car Lighting Co.]

"That is, if it were high enough up."

"Of course."

"Just how quickly does the earth's curve come into play, Father? I know the earth is round, of course, but, somehow, it seems so big that one never thinks of taking it into any practical account."