growth, since the trochas are in general of the full width of the canal at the start, narrowing down to 480 feet at the rear light. All lights, beacons and buoys are white, and are distinguished from one another by characteristic flashes. Gas and electricity are used for illumination, preferably electricity where feasible. Inaccessible lights are operated by means of compressed acetylene dissolved in acetone. The locks are illuminated by means of 400-watt tungsten lamps on concrete posts, with concrete reflectors, having a lighting effect superior to that of an ordinary arc lamp. The lamp is 30 feet above the coping and is screened by concrete skirts, so as to cut off the direct light rays longitudinally of the locks, thus keeping the glare out of the navigator's eyes. THE PANAMA CANAL PART III SANITATION-COSTS OF WORK-ELEMENTS OF SUCCESS-CONCLUSION BY REUBEN E. BAKENHUS, S. B. CIVIL ENGINEER U. S. NAVY SANITATION-COSTS OF WORK-ELEMENTS OF SUCCESS-CONCLUSION SANITATION To regard the sanitation work as a mere contributory element to a successful culmination of the canal construction work does not, perhaps, place it upon the high plane that it deserves. Rather should we regard it as one manifestation of the great progressive movement that is now pervading civilization and that regards the prevention of disease as of more importance than its cure, and in its execution requires the cooperation of the physician, the bacteriologist, the engineer, and the administrator. The Panama Canal is undoubtedly the most marked single example the world has seen of the intelligent and thorough application of the principles of sanitation. In many other parts of the world, and for years, such principles have been applied in preventing contamination of water supplies, in the purification of sewage, in the control of epidemics and in other important sanitary measures; but none have had the opportunity to display in so marked and convincing a way the great benefits to be derived, especially with the example of the French experience for a background. In no case has more been done to educate the world in general in the need and effectiveness of the application in a practical way, under control of experts, of the scientific prin |