FISH ACCLIMATISATION. 395 



clotted matter had accumulated in the gravel and scarcely seen ; 

 and which I felt must be veiy injurious to the whole fry, and I 

 think was a great cause of the gill fever which used, for the first 

 few years, to carry off so many of the young fry. Secondly, I 

 wanted to allow the water to flow beneath as well as above both 

 the ova and the fry. And thirdly, I wanted a better method 

 in shifting the fry from one trough to another, while I cleansed it 

 out thoroughly and let in fresh water, which the perforated trays 

 enable me to do so quickly and without the least injury to the fry. 



The first tray I had made answered very well, and your Lordship 

 approved of it and gave me permission to order Mr. Tillett to make 

 eight more, suggesting that the next should be made in a white 

 metal, which would be purer than the zinc. 



When I received your Lordship's first letter I could not recollect 

 the year I had the first one made, so wired to Mr. Tillett to give 

 me the date on which he made me the first trough. His answer I 

 inclose. 1 



I was very much interested and got some useful hints on my 

 visit to Huningue, in Lorraine, to which your Lordship so very 

 kindly sent me, there they hatched out the ova on glass rods, just 

 in a wooden frame about two inches from the bottom of trough, the 

 glass rods the thickness of a slate pencil, and far enough apart to 

 support the eggs without touching each other, and as the young 

 fry began to hatch out they would soon riddle off on to the bottom 

 of the trough, but there was no gravel, as soon as they began to 

 feed they were turned out into small streams in the grounds 

 beautifully arranged and adapted for them. 



I think that it must have been after my visit there that I advised 

 your Lordship to allow me to do away with the gravel in the 

 troughs. 



I have the honour to be, my Lord, 



Your Lordship's most obedient and humble Servant, 



GEORGE DEANE. 



March, 1885. 



1 Sir, I made one perforated zinc tray on the Thirtieth of October, 1873, 

 and eight more trays January the Nineteenth, and eighteen tin metal trays 

 June 1876. 



T. TILLETT, 



Ironmonger and Plumber, 

 Mr. George Deane. Stamford, 



