READING THE RIDDLES OF THE ROCKS 99 



Let us, however, suppose that the reconnoissance has 

 been successful, and that an outcrop of bone has been 

 found, serving like a tombstone carven with strange 

 characters to indicate the burial-place of some primeval 

 monster. Possibly Nature long ago rifled the grave, 

 washing away much of the skeleton, and leaving little 

 save the fragments visible on the surface; on the other 

 hand, these pieces may form part of a complete skeleton, 

 and there is no way to decide this important question 

 save by actual excavation. The manner of disinterment 

 varies, but much depends on whether the fossil lies in 

 comparatively loose shale or is imbedded in the solid 

 rock, whether the strata are level or dip downward 

 into the hillside. If, unfortunately, this last is the 

 case, it necessitates a careful shoring up of the excava- 

 tion with props of cotton-wood or such boards as may 

 have been brought along to box specimens, or it may 

 even be necessary to run a short tunnel in order to get 

 at some coveted bone. Should the specimen lie in shale, 

 as is the case with many of the large reptiles that have 

 been collected, much of that work may be done with 

 pick and shovel; but if it is desirable or necessary to 

 work in firm rock, drills and hammers, wedges, even 

 powder, may be needed to rend from Nature her long- 

 kept secrets. In any event, a detailed plan is made of 

 the excavation, and each piece of bone or section of rock 

 duly recorded therein by letter and number, so that 

 later on the relation of the parts to one another may be 

 known, or the various sections assembled in the work- 

 room exactly as they lay in the quarry. Bones which lie 

 in loose rock are often, one might say usually, more or 

 less broken, and when a bone three, four, or even six 

 feet long, weighing anywhere from 100 to 1,000 pounds, 

 has been shattered to fragments the problem of remov- 

 ing it is no easy one. But here the skill of the collector 



