But the fourth was the most potent reason of all why the lock system was adopted. On the Isthmus of Panama the rainfall amounts to 130 to 150 inches annually. Sometimes the precipitation will amount to 10 or 12 inches in twenty-four hours. The Chagres river is the only agency for the drainage of a vast area of water-shed in the Caribbean sea. Therefore, at times the Chagres river might be a small, inconsequential stream that a boy could wade across, and yet before twenty-four hours had elapsed, because of a heavy rainfall, it might have swelled into a raging torrent that would wreck the strongest battleship of the American navy. The large volume of water discharged by the Chagres river could not be turned into the canal proper, as the currents and the rush of flood waters would soon impair the banks of the canal. The Lock System Adopted Therefore it would be necessary, under the sea-level type of canal, to construct a series of embankments and dams that would be far more expensive to build and keep in repair than would be one great dam over the course of the Chagres river. Besides, the safety of the lock system would be much greater than that of the sea-level type. These were the reasons which finally controlled the determination of the engineers to construct a lock system of canal. After the type of canal was decided upon, the next step was the assemblage of the force of laborers and the mechanical appliances necessary for the physical operations. In order to carry out this scheme, a commission was originally appointed, composed half of civilians and half of military officers. The first engineers were selected as being the most eminent of their profession, and taken from civil employment. But great difficulties were encountered in perfecting the proper kind of an organization to successfully complete this stupendous project. The engineers taken from private life and entrusted with the work, after a little experience on the Isthmus, would be offered greater inducements to abandon their Governmental employment and take some other position, generally far more lucrative, in the United States. And so, either through accident or design, the Canal Commission lost the services of such men as Wallace, Stevens, Shonts, Grunsky, and other noted engineers, and again it seemed as if canal operations would be badly crippled for want of the right kind of men to direct the work. Army Engineers Installed This tendency of the civil engineers to leave their employment caused much concern to the President and Congress, and finally President Roosevelt, with his characteristic acumen, decided that he would place the work of canal construction under the army engineers entirely. So, at his suggestion, Congress reframed the law of the Canal Commission, and President Roosevelt remarked that under the new law he would put army engineers on the job, and that they would either stay there until it was done or get out of the army.