When the engineers build a Brooklyn bridge they introduce an element which they call the factor of safety. It is their usual procedure to estimate the greatest weight which their structure may be called upon to bear under any conceivable circumstances and then they make it strong enough to stand a number of times that weight. This additional strength is the "factor of safety"; it is never called into use, of course, but the consciousness that it exists gives the public a sense of security which it could obtain in no other way. We adopted a similar policy in transporting these millions of American boys to Europe. We also had a large margin of safety. We did not depend upon one precaution to assure the lives of our soldiers; we heaped one precautionary measure on another. From the embarking of the troops at New York or at Hampton Roads to the disembarkation at Brest, St. Nazaire, La Pallice, Bordeaux, or at one of their other destinations, not the minutest safeguard was omitted. We necessarily thus somewhat diminished the protection of some of the mercantile convoys--and properly so. This was done whenever the arrival of a troop convoy conflicted with the arrival of a merchant convoy. Also, until they reached the submarine zone, they were attended by a cruiser or a battleship whose business it was to protect them against a German raider which might possibly have made its escape into the ocean; the work performed by these ocean escorts, practically all of which were American, was for the most part unobtrusive and unspectacular, but it constitutes a particularly fine example of efficiency and seamanlike devotion. At Berehaven, Ireland, as described above, we had stationed three powerful American dreadnoughts, momentarily prepared to rush to the scene in case one of the great German battle-cruisers succeeded in breaking into the open sea. Even the most minute precautions were taken by the transports. The soldiers and crews were not permitted to throw anything overboard which might betray the course of a convoy; the cook's refuse was dropped at a particular time and in a way that would furnish no clue to a lurking submarine; even a tin can, if thrown into the sea, was first pierced with holes to make sure that it would sink. Anyone who struck a match at night in the danger zone committed a punishable offence. It is thus apparent why the Germans never "landed" a single one of our transports. The records show only three or four cases in which even attempts were made to do this; and those few efforts were feeble and ineffectual. Of course, the boys all had exciting experiences with phantom submarines; indeed I don't suppose that there is a single one of our more than 2,000,000 troops who has not entertained his friends and relatives with accounts of torpedo streaks and schools of U-boats.