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GUIDEBOOK OF THE WESTERN UNITED STATES. 



Junction they begin to lose some of their pictiiresqueness on account of 

 their distance from the observer. The red cliffs on the south become 

 more prominent and are much more dissected into fantastic forms 

 than they are south of Grand Junction. About 11 miles west of 

 Grand Junction the pillars, towers, buttresses, columns, and domes 

 become so striking that an area including them, opposite Fruita, 

 has been set aside by the Federal Government as the Colorado 

 National Monument. By this means they will be preserved and 

 made accessible to the general public. One of these picturesque 

 forms is shown in Plate LXXVIII. Fruita, as its 

 Fruita. name implies, is the center of an extensive fruit- 



Eievation 4,510 feet, raising district, but the best part of this district is 

 Denve^ 46° miles. on the terrace north of the town. Much of this land 

 is devoted entirely to the raising of fruit; but, as 

 shown in Plate LXXVII, A, other crops are raised between the 

 trees while the orchard is maturing. 



Just west of Fruita the railroad crosses Little Salt Wash and Salt 

 Wash, two streams that head at the base of the Book Cliffs, about 



fgrests, and by irrigation and power 

 companies at critical periods, espe- 

 cially during low water. 



In determining the flow of a river 

 the height of the water is first meas- 

 ured on a fixed scale called a gage. A 

 local observer reads the gage height 

 morning and evening and records the 

 reading. If the record at the station is 

 likely to be of great value, or if the 

 station is in a remote place, it is de- 

 sirable to use an automatic gage, which 

 draws a curve on a chart showing con- 

 tinuously the height of the water, in- 

 cluding every fluctuation. In May and 

 June the warm days and cold nights 

 cause alternate melting and freezing 

 at the headwaters of streams that head 

 in high mountains, so that they rise 

 and fall regularly during a 24-hour 

 day. The extreme daily variation may 

 amount to 1 or 2 feet. On a gage that 

 is placed near the head of the stream 

 the highest stage will be reached dur- 

 ing the day and the lowest during the 

 night, but on one that is placed some 

 distance downstream the highest stage 

 may be reached during the night and 

 the lowest during the day. 



From the gage height and the con- 

 tour or cross section of the stream 



bed at the gage, as determined by 

 soundings made at several points in 

 a line across the stream, the area of 

 the cross section at the point of 

 measurement is computed. The veloc- 

 ity of flow is measured with a cur- 

 rent meter, and from the velocity and 

 the area of cross section the quantity 

 of water flowing past the gaging sta- 

 tion can be determined. As the cur- 

 rent strikes against the cups of the 

 meter it causes them to revolve, and 

 the revolutions in a given time are 

 counted by means of an electrical 

 make-and-break contact to determine 

 the velocity of the current in feet per 

 second. 



In low water the meter is held on a 

 rod and the engineer makes his 

 measurements by wading. He first 

 stretches a line across the stream to 

 determine its width and then sounds 

 every few feet across to determine its 

 depth. Lastly he measures with the 

 meter the velocity of the water at 

 each point of sounding. Then, as he 

 knows the width and depth of the 

 stream, he can easily calculate the 

 number of cubic feet of water passing 

 this station each second (usually 

 abbreviated to "second-feet") when 



