198 Proceedinc/s of the Wernerian Society. 



Professor Jameson then exhibited finely preserved specimens of the 

 following large fishes, taken lately in the Frith of Forth, and chiefly 

 in Aberlady Bay : — 1. A Tunny, 8 feet long, and five feet 6 inches 

 in circumference where thickest ; 2. Portbeagle Shark, 7 feet 3 inches 

 l6ng, by 4 feet in circumference ; 3. Great Sunfish, 5 feet 2 inches 

 in length, and 2 foet 8 inches in depth ; and, 4. Conger Eel, 6 feet 

 6 inches long, 1 foot 10 inches circumference. The Professor also 

 exhibited a beautifully spotted Seal, 5 feet 6 inches long, 4 feet 3 

 inches circumference, which had been entangled and drowned iti A 

 herring net off Inchgarvey, near Queensferry. 



April 16. — Professor Jameson, President, in the Chair. 



The assistant Secretary read a memoir, giving a description of a 

 magnetical instrument invented and constructed some years ago by 

 Mark Watt, Esq. of Edinburgh, which, standing upon a table in any 

 room, and secluded under a crystal shade, points in the direction of 

 the wind. This instrument is formed of a thin bar of wood, of three 

 or four inches long, which traverses, like a compass, upon a steel pivot, 

 by means of an agate-capsule inserted into the wood. Three or four 

 magnets are affixed to one end of the bar of wood, which has a slit 

 one-third of its length to receive them. They are placed in a line, 

 at a distance of half an inch from each other. The magnets are very 

 light, being pieces of the mainspring of a watch, made straight, of 

 different lengths, increasing from one inch to three. They are fixed 

 quite perpendicular to the horizon, and therefore deprived of polarity, 

 with all the south poles uppermost and north undermost. The in- 

 strument is not a perfect vane ; for although the bar of wood stands 

 exactly according to the direction of the wind, it is indifferent to it 

 which end it turns towards the point the wind blows from. Yet 

 several rather interesting deductions in physical science can be drawn 

 from it. It evinces the connexion between magnetism and electricity. 

 It also renders it probable that our variable winds are caused by elec- 

 trical currents, as this instrument anticipates the changes of the wind 

 by a quarter or sometimes half an hour. The instrument was ex- 

 hibited and explained by Dr Glover. 



Mr John Goodsir read a paper by Mr H. D. S. Goodsir on the 

 metamorphoses of Carcinus and Pagurus, and on some new species of 

 Caprella (see p. 174.) 



Dr Robert Hamilton then read a paper, entitled : Report on the 

 more recent investigations cdncerning the structure, habits, and eco- 

 nomic uses of Fishes. 



