1923] EDWARDS. SECOND SEASON AT GRAND CANYON 55 



is about five feet. The floor of the bridge is fifty feet above the river 

 at ordinary water level, which serves to protect the bridge from the 

 sudden and destructive floods to which this river is subject. Only 

 one mule is allowed to proceed across the bridge at a time, as seen in 

 the illustration just mentioned, and the passage of a long train of 

 mules occupies several hours. The bridge sways slightly as it is 

 crossed, but it is anchored securely in place by guy ropes. 



Just up stream from the bridge is located the station at which an 

 observer of the United States Geological Survey daily measures the 

 height and velocity of the water, this being one of those stations which 

 furnish the data for computing the yearly water supply of the United 

 States. At the time of our crossing, three small boats were moored 

 on the shore a little below the bridge. These were being used to 

 transport a survey party engaged in making an accurate map of the 

 rapids and waterfalls of the river from Lee's Ferry to the lower end of 

 the Grand canyon. This expedition had been sent out by the United 

 States Geological Survey under the command of Colonel Birdseye. 

 The boats they were using had water-tight compartments fore and 

 aft, and were constructed as lightly as possible in order to facilitate 

 their handling at the many portages which it was necessary to make, 

 A boat of this general type has been used by every expedition which 

 has made a successful descent of this river since the time of Major 

 Powell's first exploration in 1869. 



A short distance beyond the bridge we arrived at Phantom Ranch, 

 which is situated on Bright Angel creek near its mouth. Unlike the 

 Colorado, the Bright Angel is usually clear and cold, and the water is 

 "sweet," affording a welcome relief to travelers who have, for several 

 days, been drinking tepid water carried in canteens and too often ob- 

 tained from somewhat alkaline springs or streams. This stream has its 

 source in springs on the north rim of the canyon and throughout its 

 course is practically one continuous rapid. It probably has the great- 

 est fall of any stream of similar length in the world, as its waters de- 

 scend nearly six thousand feet in eighteen miles. The ranch consists 

 of a group of stone buildings erected for the use of tourists. The 

 surroundings have been left in their natural condition as nearly as pos- 

 sible and the artistic treatment of the buildings themselves makes this 

 a very alluring spot in an otherwise inhospitable region. 



From here the trail leads directly up the canyon of Bright Angel 

 creek. In its lower portion this is a very deep and narrow gorge cut 

 into the solid granite, the perpendicular walls coming so close together 

 that it is often necessary to travel for considerable distances in the bed 



