If one who has never seen a lock canal is to get a proper idea of what part the locks play in the Panama Canal, he must follow attentively while we make an imaginary journey through the canal on a ship that has just come down from New York. Approaching the Atlantic entrance from the north, we pass the end of the great man-made peninsula, jutting out 11,000 feet into the bay known as Toro Point Breakwater. It was built to protect the entrance of the canal, the harbor, and anchorages from the violent storms that sweep down from the north over that region. Omitting our stops for the payment of tolls, the securing of supplies, etc., we steam directly in through a great ditch 500 feet wide and 41 feet deep, which simply permits the ocean to come inland 7 miles to Gatun. When we arrive there we find that our chance to go farther is at an end unless we have some means of getting up into the beautiful lake whose surface is 85 feet above us. Here is where the locks come to our rescue. They will not only give us one lift, but three. When we approach the locks we find a great central pier jutting out into the sea-level channel. If our navigating officers know their duty they will run up alongside of this guide wall and tie up to it. If they do not they will run the ship's nose into a giant chain, with links made of 3-inch iron, that is guaranteed to bring a 1,000-ton ship, going at the rate of 5 knots per hour, to a dead standstill in 70 feet. When we are once safely alongside the guide wall, four quiet, but powerful locomotives, run by electricity, come out and take charge of our ship. Two of them get before it to pull us forward, and two behind it to hold us back. Then the great chain, which effectively would have barred us from going into the locks under our own steam, or from colliding with the lock gates, is let down and we begin to move into the first lock.