148 ROYAL SOCIETY OF CANADA 



larity of bottom is mentioned, also, by Fischer-Benzon (p. 11), and others, 

 though the older writers a})pear to have believed that the highest are over 

 the deepest parts. 



The islands bearing trees are, on the Spruce Lake bog, usually the 

 summits of rocky knolls, but in the Lepreau bog this is not the case, for 

 soundings of over 12 to 14 feet occur among them. The islands are not 

 persistences from earlier times, for when they are dug up, they are 

 found to extend down only a foot or two, and below them is pure moss 

 to the bottom. The oldest tree I could find upon them was 6| cm. 

 diameter, and had 95 rings. 



A leading characteristic of ])eat bogs is the great amount of water 

 they contain and its coldness. The raised bogs are formed, as all students 

 of them agree, by the pure Sphagnum growing uj)ward and carrying 

 the water by capillarity with it. There is, however, one fact about them 

 which I do not iind discussed in an}" of the peat-bog literature accessible 

 to me, i. e., the presence of much standing water near the surface of the 

 higher parts. On the Lepreau bog, near its highest part (between B and 

 X, Fig. 2), I made several holes a foot or two deep, and in them several 

 inches of water always collected. This shows that there is an immense 

 amount of water in a hydrostatic, as well as a capillar}', condition in the 

 bog ; and the question arises, what prevents it from flowing out from the 

 great spongy structure by its own weight down to its proper level ? To 

 some extent it does this, inasmuch as the extreme margin of the bog is often 

 very wet ; as, for example, at A. Fig. 2, but most of it remains at the higher 

 levels. The only answer to this puzzling question in hydraulics, that 1 

 can suggest, is the following : The Sphagnum is able, by capillarity, 

 to raise water to about 12-J3 feet above the water level of the basin over 

 which the bog is growing, and the meaning of this height, which is 

 characteristic of the raised bogs, is that this represents the extreme height 

 to which the Sphagnum can, by capillarity, raise the water above the 

 surface level of the basin. Perhaps, with a larger suppi}'. it can raise it 

 somewhat higher, and hence gi*ow higher in wetter seasons or periods. 

 The water held by capillarity, not onl}^ in the moss-tissues, but also be- 

 tween the compacted leaves and stems, is held there so strongly that 

 when more water is added from above, as from rainstorms, the capillary 

 water yields and falls but slowly, so that the rainwater stands for some 

 time before it is absorbed. It can hardly be believed that it can stand 

 thus indefinitely, for what would lu)ld it u)) ? This view could be tested 

 by observing whether the quantity of standing water diminishes regularly 

 after rainstorms.' The weight added to one of these great bogs during 



1 In July, 1897, I mado such a test, as follows : 1 dug a row of 12 pits in the moss 

 at intervals from A to X (Fig. 2), and set stakes in them driven 4 feet into the bog, 

 and on these placed gauges. Morning and evening for seven days the level of the 

 water on these was read. These figures, tabulated, show clearly that after a rain- 

 storm the hydrostatic water in the bog steadily but slowly falls, and also, what is 



