1889.] on Beacon Lights and Fog Signals. 433 



French Lighthouse service ; but, for efficiency, and adaptability to 

 meet the rough duty to which floating lights are occasionally sub- 

 jected, in stormy weather and collisions, this system has been found 

 to be inferior for this service to the catoptric. 



An interesting experiment was recently made by the Mersey 

 Docks and Harbour Board with the electric arc light, on board one of 

 their light-vessels at the entrance of the Mersey, but unfortunately it 

 did not jDrove successful. The present difficulties exj^erienced afloat 

 with this powerful illuminant will doubtless be overcome, and it will 

 be found to be, as in lighthouses, by far the most efficient illuminant 

 for some special stations, where a higher intensity tLan can be obtained 

 with flame luminaries is demanded. Experiments have been in pro- 

 gress during the past two years at the " sunk " light- vessel, off the 

 coast of Essex, for maintaining electrical telegraphic communication 

 with the shore for reporting wrecks and casualties in the locality. 

 This vessel is connected with the Post Office at Walton-on-Naze, 

 through nine miles of cable. The instruments adopted are the 

 Wheatstone A.B.C. " Morse," and the Gower Bell telej^hone — the 

 telephone for the first time for this purpose on board a vessel at sea, 

 and its efficiency has been found to be so perfect, that it is preferred 

 by the operators to the telegraphic instruments. Many difficulties 

 have been experienced in maintaining reliable communication during 

 stormy weather, owing to consequent wear and tear of the connections 

 with the vessel, but the system, whiclrwas designed and carried out 

 by the Telegraphic Construction and Maintenance Company, is now 

 working satisfactorily. Unfortunately, however, it is found to be too 

 costly for adoption, except in very special cases. 



In 1876, Mr. Julius Pintsch, of Berlin, patented in this country 

 his system of illuminating buoys or other floating bodies by com- 

 pressed oil gas, and in 1878 one of these buoys was experimentally 

 tried at sea with success by the Trinity House. The system is 

 similar to that previously adopted by Mr. Pintsch with great success 

 in the lighting of railway carriages, but with the addition for buojs 

 of a specially constructed lantern, containing a small cylindrical lens 

 for a fixed light. Through the kindness of the Pintsch's Lighting 

 Comjjany we have here one of these a23paratus, producing an intensity 

 in the beam of about twenty candle units. With the charge of gas 

 contained in the buoy the light is shown continuously, night and day, 

 from two to four months, according to the dimensions of the buoy, 

 without re-filling or requiring any other attention, except occasional 

 cleaning of the lens and the glazing of the' lantern. In 1883, 

 Mr. William B. Eickman patented a very ingenious addition to this 

 apparatus for producing occulting or flashing light. The apparatus 

 is automatically worked by the issuing compressed gas on its way 

 from the buoy to the burner. After passing the regulator, where the 

 pressure of the gas is reduced for burning, it enters a cylindrical 

 chamber, covered with a diaj^hragm of very flexible specially jirepurcd 

 leather ; this diax)hragm, on being slightly raised by the inflowing 



