1885.] NEW YORK ACADEMY OF SCIENCES. 65 



fully and saved it. To have removed it would have seriously 

 disfif^iired the top of the obelisk. This plan was curi-ied out all 

 through the work, and there is a great deal of thcsui-face which, 

 fhougli hollow, will nowstand for a great number of years, whieli, 

 liad it been left unprotected, Avould soon have fallen away. 

 When the work of cleaning had sufficiently advanced, we pro- 

 ceeded to apply the waterproofing compound. This was on 

 November 6th, and we continued the work until November L'jth, 

 Avlien all was finished. Some part of the time, the weather was 

 very boisterous, one could scarcely stand on the scaffolding, the 

 Avind had such force, especially on November 9th and lOth. 



As before stated, 780 ])ouuds of pieces of decayed gi'anite 

 were taken from the obelisk, which proves beyond question 

 that the stone, though only exposed four and one-half years, 

 could not withstand the destructive influences of this climate. 



What I have recently accomplished clearly proves also that 

 certain statements made in the public press are unreliable, 

 viz., the calculation "that it would require 58,056 years to 

 remove from the plinth a shell one centimetre in thickness, 

 and weighing 631,652 grams" (or 1,338 pounds avoirdupois), 

 and that " the waste in a centui-y would therefore be scarcely a 

 perceptible amount," as well as the concluding summing n]> that 

 " we need, therefore, be under no apprehension that the obelisk 

 Avill seriously suffer from the effects of our climate." 



(Secondly, it proves that " the suggestions of certain foreign- 

 ers, who had visited Central Park, and said that if the obelisk 

 Avas not protected, the frosts and snows of our severe winters 

 would soon make more of an impression upon the stone than tlie 

 thousands of years under an Egyptian sun," were reasonable and 

 Avell founded. 



Thirdly, that "a hot compound could not be made to enter 

 the stone, without the use of a greater heat than would be possi- 

 ble without injury to the stone," was a groundless fear, because 

 the successful heating and applying of the hot melted paraffin 

 compound to the sui'face has been actually done without causing 

 any injury whatever to the stone. This is a fact, not an opinion 

 or a theory, and it speaks for itself. But for these unfortunate 

 expressions of opinions from high authorities, made through the 

 public journals, doubtless the obelisk would have been treated 

 years ago, and much of this valuable and interesting relic and 

 record of the ]iast, which has now been irretrievably lost to pos- 

 terity, would have been saved. 



It was feared by some persons, as I have just stated, that this 

 Avaterproof compound could not be applied to the obelisk, Avith- 

 out serious risk of injury. The trial has been made and no 

 <lamage at all has been done, for, by a careful method of appli- 



