[105] 



Iponb OLifc.* 



Lectures delivered to the Albany Naturalists' Club, Edinburgh, 



By William Evans Hoyle, M.A. (Oxon), 

 F.R.S.E., M.R.C.S., 



Naturalist to the " Challenger " Expedition Commission. 



First Lecture, Nov., 1884. 



Plate XIL 



IT is not necessary for me to commence this Lecture by 

 defining a pond. The definition of a lake, which you can 

 find in any of the geography-books, will do as well if you add 

 the words " a little smaller." It is possible that many of you may 

 have thought that a pond was here, there, and anywhere, because 

 it happened to be placed there when the world was made. But if 

 you look at any of the ponds that you know, you will see that 

 there are certain conditions which are essential to there being a 

 pond in any particular place. You will find that there is water 

 falling, as rain, upon all the country round about, and as this 

 water falls upon the hills, it runs down their sides into the valleys, 

 where it forms streams : and then you can easily imagine that 

 there will be certain places where, owing to the valley being partly 

 filled up, the water will collect ; and this is the manner in which 

 every lake and every pond is formed. If you will remember the 

 Braid Hill pond, there are hills all round it, and from these hills 

 little streamlets trickle down into the pond. But even on the low 

 part where the road runs, the road is higher than the pond, and 

 so it keeps the water in. There is only one small channel where 

 the water runs out and finds its way down into the valley. 



The surrounding hills, too, determine the nature of the bottom 

 of the pond, which consists simply of small fragments which 

 have been washed down from them, so that it contains the 



* The reader is requested to look upon this Lecture not as a contribution 

 to knowledge, but merely as an attempt to describe a few natural phenomena 

 in language as simple and free from technicality as possible. The fact that it 

 was delivered as a lecture, and is now printed from the reporter's notes, must 

 excuse the many deficiencies in literary style. 



