Lake Ramparts. 



22y 



preliminary training is necessary- — nothing but attention. 

 And the available themes are practically infinite in num- 

 ber and variety. The various insects, birds, mammals, 

 and reptiles, the varied trees, shrubs, and flowering plants, 

 the minerals and rocks, the forms of the landscape, the 

 streamxs, the snow, the winds, the clouds, — all invite and 

 repay attention; and problems appear at every turn. To 

 the professional investigator such themes are a principal 

 motive, and his purpose is to increase the sum of human 

 knowledge. For him, indeed, attention is not the only 

 requisite; he must have systematic methods of work, 

 and he must acquaint himself with the work of others 

 in his chosen field. To the business man, the professional 

 man, or the teacher seeking recreation — to the layman, in 

 a word, in scientific study — the scientific motive is sec- 

 ondary, and instead of considering the advance of science 

 he need think only of his personal profit in intellectual 

 growth and an added zest to life. 



The homily in which I have indulged may be regarded 

 as the introduction and defense of a somewhat technical 

 article ; or the pages which follow may be regarded as 

 the illustration of the theme of the homily, and an attempt 

 to develop interest in one of the minor features of Sierra 

 topography. 



On the shores of many lakes in the Sierra are rows 

 of boulders. Sometimes they are strung along, one or 

 two at a place ; sometimes massed together so as to con- 

 stitute a low ridge. They are small and large, ranging 

 up to a diameter of several feet. In every case their 

 position is close to the water, usually just at the water's 

 edge. Such boulder lines and boulder ridges are known 

 also in other regions, and have received the name of lake 

 ramparts. Two examples are pictured in the accompany- 

 ing plates. 



Whence come these boulders? Usually on the adjacent 

 land other boulders are to be found, in every way similar 

 to those at the shore except that they are irregularly scat- 

 tered over the surface. Usually, also, in the shallow 



