The Presentation of the Diplodocus 249 



position until the skeleton has been assembled, because 

 there must be room left to get under the cross-beams, so 

 that the supports which are destined to finally bear 

 the specimen may be adjusted from time to time and 

 the bolts which hold them may be tightened. Upon the 

 central base planking is laid, and on this the vertebrae 

 of the body, or barrel, are carefully assembled and put 

 into position upon two more or less horizontal steel 

 rods. When all has been carefully adjusted a steel 

 rope is bent underneath the mass in such a way as 

 to catch the temporary supports which hold the 

 vertebrae, and the whole thing is tied together. The 

 arrangement of the details is too complicated to make 

 it worth while to attempt to describe it here. The next 

 step is to slowly and carefully lift the mass into the air 

 to the height of about fifteen feet. This is accomplished 

 by means of blocks and tackles lowered from a beam, 

 which generally forms a part of the scaffold put up at 

 the outset, and is strong enough to carry a load of two 

 or three tons. In La Plata we were fortunate in finding 

 that we could make use of the iron beams which support 

 the ceiling of the room. After the backbone of the 

 monster has been lifted high into the air, the next step 

 is to screw into place the tall supports of steel, which 

 enter sockets provided at the pelvis and at the shoulders. 

 When this has been accomplished, the next step is slowly 

 to lower the mass until the steel uprights drop into the 

 sockets prepared in the base to receive them, where 

 they are at last firmly secured by nuts and washers. 

 The whole operation is delicate and not without its 

 dangers, as we learned at St. Petersburg. Our ex- 

 perience there is never to be forgotten, and I trust 

 may never be repeated. We had raised the vertebra? 

 of the backbone into the air. Six moujiks, or ordinary 



