The simplest way of reaching the Gatun dam is of course by train from Colon, a ride of perhaps twenty minutes. But a more spectacular one is by launch, either up the Canal, or around by the Chagres River from its mouth. The latter is a difficult trip however and seldom essayed. One advantage of taking the Canal is that it gives a much clearer idea of the construction of the dam than can be derived by approaching it by railroad. The first significant fact forced upon your attention in thus coming upon the dam is that it does not look like a dam at all, but rather like a long and gently sloping hill pierced at one point by a sort of masonry gate which upon closer approach reveals itself as a system of mighty locks. [Illustration: GATUN LOCKS OPENING INTO THE LAKE The skeleton structure on the left is the frame-work of the emergency dam which swings directly athwart the lock] Not very long ago there was a wide-spread apprehension in the United States, bred of a rather shallow newspaper criticism very widely republished, that the Gatun dam would prove inadequate to the pressure of the waters impounded behind it and might collapse, or “topple over”. If all who have been impressed by that gruesome prophecy could see the dam itself their apprehensions would be speedily quieted. One might as well talk of toppling over the pyramids, or Murray Hill, New York (not the structures on it, but the hill itself) or the Treasury Building at Washington. Elevations, natural or artificial, the base of which is eight to ten times their height, cannot topple over while the force of gravity continues to operate. Now the height of Gatun dam is 105 feet, and from its crest the filling of clay and rock slopes gently away on the landward side for nearly half a mile. There are more abrupt eminences on many of our rolling prairies. The face on the lake side descends somewhat more abruptly, but is still several hundred feet long before its slope ends with the bed of the lake. This face is covered with broken stone down to the “toe”--as they call the walls of rough rock between which the dirt dam was built. [Illustration: _Photo by Thompson_ GATUN LAKE SEEN FROM THE DAM] [Illustration: _Copyright, 1911, by Munn & Co. Inc. From Scientific American_ BIRD’S EYE VIEW OF GATUN DAM In the foreground the locks, only two of the three steps being fully shown. In the middle distance the spillway, through which surplus water flows into the Chagres and old French Canal]