26 LIVERPOOL BIOLOGICAL SOCIETY. 



animals collected, nor any comparison between the con- 

 tents of illuminated and ordinary tow-nets worked at the 

 same time. 



The next submarine electric hght experiments were 

 those carried out by the L.M.B.C. in May, 1888, on board 

 the "Hy^na," as detailed in last year's Eeport.* Just a 

 month later in that same summer (24th to 26th June, 

 1888) Prince Albert of Monaco! used on board his yacht 

 "Hirondelle," a tow-net lit by a small Edison incandescent 

 lamp (12 volts), supphed by a single Bunsen cell in which 

 the nitric acid was replaced by chromic acid. The battery, 

 which is let down into the sea along with the net, 

 is hermetically sealed up in an iron case, while when 

 the apparatus is used in great depths, the pressure is 

 ingeniously equalised by a tube connecting the interior of 

 the case with a strong indiarubber ball filled with air. 

 This apparatus was tried in the neighbourhood of the 

 Azores down to a depth of about twenty fathoms. 



It may be useful to state here that the ''Hyaena" is 

 fitted up with the following electric light installation I : — 

 A Gwynne vertical engine, of six nominal horse-power, 

 running at 300-400 revolutions per minute, works a Phoenix 

 compound -wound dynamo, with an effective output of 

 5,980 Watts (65 volts, 92 amperes) at 1,000 revolutions 

 per minute. There are two Pilsen arc lamps of 3,000 

 nominal candle-power each, which can be used on deck or 

 at mast head, or on the side of the ship; four Edison-Swan 

 submarine incandescent lamps of 100 candle-power, and 

 ten of sixteen candle-power each. The dynamo, being 

 compounded, allows the arc and incandescent lamps to be 



* And in Nature, vol. xxxiii., June 7, 1888. 

 t Comptes-rendus, t. cvii., July 9, 1888. 



X I ain indebted to Captain F. Young of the Liverpool Salvage Association 

 for this information in regard to the plant on board the "Hyaena." 



