THE EARN 93 



to do so. The tacksmen of the netting stations find that their 

 fishing does not pay wages till about the end of June, and as a 

 consequence the river may be said to be clear of nets in spring. 

 The Earn actual period of regular netting is therefore practically 

 July, and the three available weeks of August. Two or three spring 

 fish are generally got on the rod in the middle reaches of the river, 

 showing, as it seems to me, the possibility of better things, but such 

 fish must undoubtedly ascend very early before the temperature of 

 the river water has fallen sufficiently to make the various and serious 

 obstructions of the river act as checks. 



It is believed by many that the reason why spring fish do not 

 ascend the Earn at all freely is that the temperature of the river 

 water is lower than that of the Tay. I know of only one paper 

 which gives actual thermometric readings, 1 and these are somewhat 

 limited, being monthly means for 1888, as compared with the Tay 

 and Almond. It is interesting to note the figures for the five first 

 months of the year : 



Months. Earn. Tay. Almond. 



January - - 39'2 37'8 367 



February - - 357 37.5 34'4 



March - - - 37'1 37'4 347 



April - - - 42-8 43'6 37'3 



May - - - 49-9 46'9 



From these it would appear that during the early months of this 

 particular year, the Earn has greater fluctuations than the Tay. As 

 compared with the Tay, the Earn temperatures are 1'4 higher in 

 January, and 3 higher in May, but slightly lower in the three other 

 months mentioned. The Almond, it will be noticed, is consistently 

 lower in temperature than either the Tay or Earn. In this connec- 

 tion it is necessary to state that the Earn readings were taken at 

 Bridge of Earn, which, as already seen, is within the tidal area ; so 

 that it is just possible that some influence of the Tay may have been 

 allowed to affect the results. But certainly from the limited amount 

 of data to go upon, there does not appear to be any sufficient dis- 

 tinction in temperature to account for the absence of Earn spring 

 fish. A more important factor is perhaps the predominating volume 

 of Tay water, which acts as an inducement to incoming fish to pass 

 the rnouth of the sluggish Earn. 



Tributaries entering the lower portions of large rivers are, as a 

 rule, passed by all early-running salmon ; but upper tributaries, if 

 supplied with good volumes of water, are entered when their tem- 



X H. R. Mill, British Association Report, 1891. 



