however, in the measure of the earth's diameter, they are ridicu- 

 lously small. If you bad a globe eleven and one-half feet in diam- 

 eter, a raised line one-sixteenth of an inch high upon it would about 

 represent the height of our mountains to the diameter of the globe, 

 and the one-thousandth of the thickness of that tiny line (equal to 

 one-sixteen thousandth of an inch) would approximately represent 

 the depth of the surface which we know as soil, and with which we, 

 as food producers for the rest of the earth's population, have to do. 



If these folds, or ridges and mountains, did not exist, the earth's 

 surface would be a monotonous plain, practically everywhere equally 

 distant from the centre of the earth, except in so far as that dis- 

 tance was modified by the differences between the polar and the 

 equatorial diameters of the earth. Our streams would flow slowly 

 in the Northern hemisphere toward the northeast, and in the South- 

 ern hemisphere toward the southeast, and the large masses of 

 water would gravitate to the po-les, as those would be the portions 

 of the earth least remote from the earth's centre. The continental 

 laud masses would tend to be in the equatorial diameter of the globe 

 because the land there would be the highest, i. e., most distant from 

 the earth's centre. 



The introduction, however, of these shrinkage folds, which we now 

 recognize as mountains, completely changes these relations. Water 

 will flow downward along the lines of least resistance, and as it flows 

 will wear away the soil first and the rock next, in exact proportion, 

 other things being equal, to the rapidity of its flow. We see this in 

 the washes on our hillsides and in the constantly changing courses 

 of our stream channels. But other things are not equal. If they were, 

 the tendency to the formation of ravines and gulches, by erosion, 

 would not exist, and everywhere o-ver an equal slope the wearing 

 away of the soil would proceed evenly, and the unbroken character 

 of the country would in great measure be preserved, or more properly 

 speaking, the tendency to an even reduction of our mountains would 

 everywhere exist. 



As it is, vast discrepancies in the character o-f soils and rocks 

 occur; some yielding to erosion by flowing water more easily than 

 others and it is along such lines of least resistance that currents of 

 equal velocity carve out their valley channels to the ocean, following, 

 of course (in most instances) the trend of the larger valleys made by 

 the folds in the earth's crust. 



The one factor which is potent in giving character to the earth's 

 surface, and which we can indirectly control, is the rapidity of the 

 water flow. Under natural conditions, in a timbered country, the 

 normal tendency of the water would be to the least rapidity of flow, 

 because of the hindrances afforded, directly and indirectly, by the 



