PETRIFIED FORESTS OF ARIZONA. 307 



order that due weight be given to scientific considerations — such, for 

 example, as that of causing the park to include points at which the 

 fossil logs are actually in place and good exposures of the rock in 

 which the}^ are embedded. 



3. The area fixed upon by this survey should be correctly described 

 and made a public reserve by act of Congress, with proper provisiony 

 for its preservation. I need not further specify what I think these 

 provisions should be. Those of other similar acts, with special modi- 

 fications to suit the case, will probably suflSce. 



■i. As early as possible after the boundaries shall have becD fixed 

 there should be made a new topographical survey, which need not, 

 however, be limited to this area, but should include it. The topo- 

 graphic map resulting from this survey should be on a scale of 1 mile 

 to the inch and the contour interval should be 50 feet. The parties 

 making the survey should be instructed to give appropriate names to all 

 the more prominent objects and features, and to locate and name them 

 on the map for the future use of the public visiting the park. A 

 geological map should also be prepared on this new base. The present 

 topographic map, on a scale of 4 miles to the inch, with a contour 

 interval of 250 feet, is very inconvenient, and of little value in the 

 study of this region. 



5. No time should be lost in taking measures to prevent the parting 

 and collapse of the natural bridge. As I have shown, this is liable to 

 occur at anytime; and although it may last for hundreds of years, still 

 the danger that it may give way, and thus ruin the most important 

 feature of the park, justifies prompt attention. Engineers should at 

 least examine it at once, and if they find it insecure, as stated, they 

 should take steps to strengthen it and render it permanent, which could 

 probably be done at little expense. 



As the land on which the natural bridge is located is public land, 

 this work might be done independently of any action in the direction 

 of making it a public reserve, but it seems doubtful whether the 

 authorities could be brought to the point of actually taking action in 

 the matter unless attention be first concentrated upon it by such an 

 act as that of creating a public reservation. But if steps in this 

 direction could be taken in advance of such action, this would diminish 

 the chances of the catastrophe. 



I have the honor to be, very respectfully, yours, 



Lester F. Ward, 

 Paleontologid^ United States Geological Survey. 



Hon. Charles D. Walcott, 



Director United States Geological Survey. 



