1889.] on Beacon Lights and Fog Signals. 441 



of the Britisli Association for the Advancement of Science, when he 

 directed attention to the extreme importance of ready identification 

 of lights at sea, and proposed the use of quick-flashing lights, their 

 flashes being of longer or shorter duration ; the short and long 

 flashes representing the dot and dash of the Morse alphabet as used 

 in telegra]3hy. It was found, however, that the number of symbols in 

 one alphabetical code would not be sufficient, on a thickly lighted 

 coast, to ensure individuality, and render each distinction perfectly 

 trustworthy. Further, that very raj)id repetition of each symbol is 

 not required by the mariner, and would involve loss of accumulative 

 power in the flashes, besides incurring unnecessary wear and tear 

 in rotating heavy oj)tical apparatus. Yet much is to be done in the 

 direction of simple distinction. At the Montreal Meeting of the 

 British Association, in 1884, I submitted a paper on 'Improvements 

 in Coast Signals,' in which were suggested two aljDhabetical codes of 

 flashing lights, and one of occulting, all having the same period of 

 the symbol, viz. half-a-minute. In one of the codes of flashing 

 lights long and short flashes were proposed, as previously by Sir 

 William Thomson, and, in the other, there were proposed white and 

 red flashes. In the occulting series, long and short eclipses were 

 proposed to be substituted for the long and short or white and red 

 flashes of the flashing codes. The system has the advantage of ajppli- 

 cation to all existing lighthouse apparatus, and many lights have 

 been altered to selected symbols of eaclr of these series. 



Little was ever accomplished in the way of warning or guidance to 

 the mariner during fog, until about the middle of this century. Pre- 

 viously, a few bells had been established at lighthouses in this 

 country and abroad, and gongs of Chinese manufacture had been in 

 general use on board our light-vessels, but both instruments are now 

 acknowledged to be wanting in the efficiency now demanded in fog, 

 to meet the requirements of navigation. The first imj)ortant improve- 

 ment in fog signals, for the service of mariners, was made by the 

 late Mr. Daboll in 1851, who submitted to the United States Light- 

 house Board, in that year, a powerful trumpet, sounded by air, com- 

 pressed by horse-power. The apparatus was installed at Beaver Tail 

 Point, Rhode Island, and the favourable results obtained with it 

 stimulated Mr. Daboll, under the encouragement of the United States 

 Lighthouse Authorities, to the further development of the apparatus ;• 

 and ultimately, he employed Ericsson's Caloric Engine, as the motive 

 power, with automatic gearing for regulating the blasts. In 1854, 

 some experiments on difterent means of producing sounds for coast 

 signals were made by the engineers of the French Lighthouse Depart- 

 ment, and in 1861-2, MM. Le Gros and Saint Ange Allard, of the 

 Corps des Ponts et Chaussees, conducted a series of experiments upon 

 the sound of bells, and the various methods of striking them. In 1862, 

 Mr. Daboll submitted his improved fog trumpet apparatus of about 

 three horse-power in the blasts, to the Trinity House, who, under the 



