EXPERIMENTAL WORK. 271 



one hundred Lochleven trout, weighing 80 Ibs. These fish were 

 barely three years old, and very good specimens for their age for 

 this part of Scotland. I despatched them in four of the conical 

 yearling tanks, with 15 gallons of water in each. The tempera- 

 ture of the air was 34 F., and the temperature of the water 

 38 F. The fish were despatched in the middle of the day, and 

 the length of the journey was a little over four hours. 



On the 1 8th March I received a post-card from Lord Balfour 

 that the fish had arrived without loss or symptom of distress at 

 Tulliallan. 



Next morning I despatched a second hundred of the same sized 

 trout by the 11.30 A.M. train from Stirling, but one tank sprang a 

 leak shortly after leaving the Fishery, and the trout were divided 

 into the three remaining tanks. These fish also arrived at Tulli- 

 allan without any loss. This was the first important consignment 

 from Howietoun, and I considered, as the result of the experiment 

 of sending successfully 200 thirty-five months' old trout to Tulli- 

 allan, weighing 160 Ibs., that 24 Ibs. of trout can exist with safety 

 in 1 2 gallons of water for four hours, provided the temperature is 

 under 40 F. Therefore 2 Ibs. of trout can exist in 1 gallon of 

 water for four hours, or 1 Ib. of trout can exist in 1 gallon of water 

 for eight hours. Therefore an hour-gallon can support 8 Ibs. of trout. 



tut 

 Or, to put this in its simplest mathematical form, 9 = -^, where 



g = number of gallons, iv = weight of trout in Ibs., and = the time 

 in hours occupied in the journey. For example, suppose it is 

 required to send trout a sixteen-hours' journey from water to water 

 to know how many trout can be sent in an ordinary 40-gallon 



tank; here #=40, and =16, therefore from 9 = -%, ' 40 ~~^ J 



/. 40 = 2w>, .'. i7 = 20 Ibs. of trout, that is to say, 20 trout of 1 Ib. 

 each, or 80 trout of ^ Ib. each, or 100 trout of five to the Ib., 

 200 trout of ten to the Ib., always provided that the tempera- 

 ture of the water does not rise above 40" F. 



On the 3d April 1879 I experimented by placing 100 yearling 

 trout in a conical tank, with 12 gallons of water, at 4.40 P.M. At 



