The number of signals which can be made by permutations of 18 flags, no flag being used more than once in the same hoist, is as follows:-- One-flag signals 18 Two-flag signals 306 Three-flag signals 4,896 Four-flag signals 73,440 ------ Total 78,660 The number of signals actually provided in the old Code which can be made by the Code flags is:-- One-flag signals 4 Two-flag signals 215 Three-flag signals about 4,500 (_a_) Four-flag signals, excluding those } representing the names of places } and ships, about 8,700 } (_b_) Four-flag signals representing the } 29,600 names of places, about 3,400 } (_c_) Four-flag signals representing the } names of ships, about 17,500 } ------ Total about 34,319 The following is the number of signals which can be made by means of the 26 flags which we have adopted, no flag being used more than once in the same hoist:-- One-flag signals 26 Two-flag signals 650 Three-flag signals 15,600 Four-flag signals 358,800 ------- Total 375,076 Moreover, by using the Code pennant over and under one or two flags of the Code, the following additional signals made by not more than three flags are obtainable:-- Code Pennant over one flag 26 Code Pennant under one flag 26 Code Pennant over two flags 650 Code Pennant under two flags 650 ----- Total 1,352 It will therefore be seen that by the adoption of the eight additional flags, many of the more important signals which have at present to be made by three-flag hoists can be converted into two-flag signals, and that all the four-flag signals (excluding those representing the names of places and of ships) in the old Code can be made by three-flag signals, while between 3,000 and 4,000 new signals to be made by hoists of not more than three flags can be added. The abolition of all four-flag hoists for general signals will very greatly increase the _Rapidity_ with which communication can be held by means of the International Code of Signals.