amount saved in building, the actual cost of maintenance would be less. After being built, it would be easier to enlarge the lock canal than the sea-level canal. The law now on our statute books seems to contemplate a lock canal. In my judgment a lock canal as herein recommended is advisable. If the Congress directs that a sea-level canal be constructed, its direction will, of course, be carried out. Otherwise, the canal will be built on substantially the plan for a lock canal outlined in the accompanying papers, such changes being made, of course, as may be found actually necessary. In June 1906 Congress finally decided for a high-level canal, and the controversy was officially closed. But the friends of the sea-level scheme were by no means silenced. Whenever any serious difficulty occurred in the construction of the canal on the lock principle their voices were heard again. In fact, the conflict cannot be said to have ended until 1909, and even then it is not certain that the sea-levellers modified their convictions. CHAPTER IX. MAN AND THE GNAT. Almost at the beginning of their great task the Americans were faced with a problem which involved the success or failure of the whole enterprise. I have said something about the climate and health conditions at the isthmus. It is fairly certain that yellow fever and malaria would have wrecked the French undertaking even if there had been no other obstacles to its success. It is not less probable that if the Americans had been in no better a position to wage war with these plagues, their work at the isthmus would also have been in vain. The French had built excellent hospitals and provided efficiently for the comfort and recovery of those who were stricken with these diseases. But being totally ignorant of the sources and method of transmission of malaria and yellow fever, they could do nothing effectual in the way of prevention and eradication. They could only take the individual victim when they found him and do their best to cure him. They still believed that malaria was produced by climatic conditions, by marshy emanations, mists, and so forth. The fleecy clouds which gather round the isthmian hills in the rainy season were given the very undeserved title of "the white death" by the French workers at the isthmus. Yellow fever, again, was just as mistakenly attributed to the climate, and especially to filthy ways of living. It is not surprising that, with these misconceptions, medical skill should have been almost useless during the French occupation, and that the employees at the isthmus should have died in their thousands.