FISH-CULTURE. 273 



after 2^ hours, and the remaining 6 fish were left for five hours 

 longer, so let ivt" represent the weight and time until the removal 

 of the fish that is for 2^ hours and w"t" represent the conditions 

 from then until the end of the experiment, then wti0f + w"f* (2), 

 but to' = 12 Ibs., and w"=l2 Ibs. 1^ lb. = 10| Ibs., and ' = 2 

 hours, i.e. from 11.20 A.M. to 2 P.M., and {" = 5 hours, i.e. from 

 2 P.M. to 7 P.M. ; then substituting the value wt in (2), we get from 



(l)\".9 = ~ ~ (3). therefore g= 10^ gallons nearly ; and 



the experience of subsequent years has proved that this calcula- 

 tion is sufficiently accurate for all practical purposes. 



SEASON 1878-79. FISH-CULTURE. 



On the 1st July I counted the three-year-olds in the west 130- 

 feet wooden pond, and found 1776 trout remaining. A good many 

 had jumped out previously. I transferred the fish to the centre 

 130-feet wooden pond, in which 500 of the same lot had been left 

 from last year, making probably about 2200 trout in the pond. 

 They averaged just over 1 Ib. 



On the 2d July I moved 424 Lochleven yearlings from the 

 upper 100-feet earth pond at Craigend to the west 130-feet wooden 

 pond at Howietoun, and on the next day I moved 2709 Lochleven 

 yearlings from the upper 100-feet earth pond at Craigend, and 

 957 Lochleven yearlings from the lower 100-feet earth pond at 

 Craigend to the west 130-feet wooden pond at Howietoun; and 

 on the 19th August I emptied the ponds at Craigend, and found 

 548 Lochleven yearlings in the upper and 743 Lochleven yearlings 

 in the lower. These I also transferred to the west 130-feet wooden 

 pond at Howietoun, making 5381 hi all. 



On the 7th July a three-year-old Lochleven trout jumped out 

 of the centre 130-feet wooden pond at Howietoun. It measured 

 1 4 '6 inches, and weighed 1 Ib. 5 oz. I consider this a very impor- 

 tant record, as the fish could not have been more than forty-two 

 months old, although I have reason to believe it was by no means 

 the largest fish in the pond, as I find on the 7th March 1878 a 



s 



