Bert Wilson at Panama

by J. W. Duffield

In these locks were three chambers, lower, middle and upper. Each was a thousand feet Long, one hundred and ten feet wide and eighty-one feet deep. As the vessel enters the lower chamber, it finds there a depth of over forty feet. The gate is closed and the water pours in, lifting the vessel as it rises. In fifteen minutes, the water rises over twenty-eight feet. Now the ship has reached the middle chamber, and again the gates are closed and the process repeated. The upper chamber is the last stage, and then the vessel reaches the artificial lake of Gatum. It has climbed eighty-five feet in about ninety minutes.

"Just like climbing a flight of stairs," exclaimed Dick.

"Precisely," said Bert. "Where a train climbs a mountain by a steady grade, the vessel leaps up to the top in three jumps."

"Think of trying to lift one of those enormous vessels with a derrick or a crane," murmured Tom; "and yet how gently and easily the water does it by pushing up from underneath."

"Look at the width of those concrete walls," pointed Bert. "Fifty-two feet thick!

"Well, twenty-five million dollars will do a lot, and I've read that it cost that much for these locks alone. And that's only a fraction of the entire work."

At every turn, they came across something that evoked their wonder and admiration. Most of the figures and statistics connected with the colossal work they were already familiar with, but the information thus gained was, in a certain sense, hazy and unreal. It was seen through the mirage of distance, and not until their eyes actually saw the work in course of construction, did the knowledge lying in their minds, take a sharp and clearly cut outline.

As they moved about the dam, they came in contact with many of the engineers connected with the work. These were picked men, Americans like themselves, and of the very highest class of skilled engineers. They were glad to meet the young fellows from the States—"God's country," as they named it to themselves, in moments of homesickness—and the intelligent interest of the boys, in marked contrast to many of the "fool questions" put to them by the general run of tourists, made them eager to impart to them all they wanted to know. They grew "chummy" at once, and by the time the boys had spent a half a day in their inspection, they knew more about it than they would have gained in a month of reading.

Among other things, they learned that the locks were the greatest reinforced concrete structure in the world. They had been built in sections, thirty-six feet long, and these had been joined together so as to make one gigantic rock, thirty-five hundred feet long and three hundred and eighty-four feet wide. This reached down fifty feet under tide, and towered one hundred and fifteen feet above the level of the sea. The concrete necessary was brought in barges that if strung along in one tow would have stretched from Colon to the southern coast of the United States, a distance of fifteen hundred miles. Great masses of steel were first erected, and then the concrete was poured into these by giant mixers.

The wall at the west wing held back the waters of the Chagres River. This was allowed to spread out into a lake, covering nearly two hundred square miles, at a level of eighty-seven feet. From this the water was drawn to feed the locks, and even in the dryest season would prove sufficient for that purpose.