CORRESP ONDENCE. 



43 



CORRESPONDENCE. 



THE SCIENTIFIC EXPLORATION OF 

 MAMMOTH CAVE. 



Messrs. Editors. 



IT is due to the trustees of Mammoth 

 Cave to state that, while guarding their 

 property rights, they have uniformly en- 

 couraged scientific investigation. Certain 

 maps may have been modified and others 

 suppressed ; but, on the other hand, it 

 should be noted that Manager Klett, with 

 authority from the trustees, let me exhibit 

 before the American Association the results 

 of his own accurate survey of the cave, 

 which it is his intention to publish when 

 it is completed, in a form that can be de- 

 pended on for all scientific ends. He laid 

 110 restraint on the members of the Asso- 

 ciation who visited the cave, at the close of 

 the Cincinnati meeting, but allowed them to 

 use barometers, pedometers, and other in- 

 struments. I regarded his request as rea- 

 sonable that I should not give the scale on 

 which his map is drawn, nor my own table 

 of distances. The dimensions of domes, pits, 

 and several large chambers were given, and 

 other particulars of interest, that could not 

 have been obtained but for the liberal aid 

 of the manager. 



Let me add, as to the temperature of 

 the cave, that the maximum is 56 Fahr., 

 the minimum 52A- , and the annual average 

 53. The latter may also be taken as the 

 mean temperature of the earth's crust in 

 the locality of the cave, namely, latitude 37 

 14' 5" ; longitude west from Washington, 

 9" 4' ; and at an elevation of about five 

 hundred feet above the level of the sea. 



Please make the above corrections in 

 your very gratifying report of my remarks 

 before the American Association, and oblige, 

 Yours, respectfully, 



H. C. Hovkt. 

 New Haven, Connecticut. December 1, 18S1. 



[It is proper to add that, in making up 

 our notices of the papers read at the last 

 meeting of the American Association, we 

 had to depend largely upon the reports of 

 the proceedings in the daily papers, which 

 are often imperfect in many points, and can 

 not always be relied upon as correctly rep- 

 resenting the author's meaning. Editor.] 



A CORRECTION. 



Messrs. Editors. 



In the December number of the " Month- 

 ly " I have coupled the names of Torel 

 and Dana as believing that Greenland was 

 the source of the American ice-sheets. If I 



had read Frofcssor Dana's remarks more 

 carefully, I should have discovered that he 

 pronounced this view "absurd.'' Further- 

 more, in referring to the Canadian highlands 

 as the starting-point of this ice, the early 

 view of the same author was mentioned, but 

 not the later one. Since 1873, Professor 

 Dana has taught that the ice probably 

 flowed from the Canadian (Laurentian) high- 

 lands across the St. Lawrence Valley into 

 New England over the higher mountains, 

 upon a lower over a higher level to the sea ; 

 and the motion was occasioned in great meas- 

 ure by the enormous ice accumulations of 

 the north overflowing southerly. I regret 

 exceedingly the misstatements. 



C. H. Hitchcock. 

 Hanover, New Hampshire, December 7, 1881. 



A TYPOGRAPHICAL ERROR. 



Messrs. Editors. 



On page 267 of the December number, 



at the bottom of the first column, 



Boston 164 



Cincinnati 155 



should read 



Boston 164 



Cincinnati 155 



The Cincinnati members present at Bos- 

 ton were counted from Ohio, the Boston 

 members at Cincinnati from Massachusetts. 



E. 



November 24, 1S81. 



AN ARCHAEOLOGICAL QUESTION. 



Messrs. Editors. 



The following inscribed objects have 

 been found within the limits of the United 

 States ; 



1. The Grace Creek stone, West Vir- 

 ginia. 



2. The Pemberton axe, Pemberton, New 

 Jersey. 



3. The Davenport slates, Davenport, 

 Iowa. 



4. The Piqua tablets, Piqua, Ohio. 



It is evident that, if they are authentic, 

 they are of immensely more importance 

 than implements or pottery. 



If they are " archaeological frauds," 

 gentlemen who follow that branch of science 

 should lend their aid to convict them. 



Under these circumstances, and having 

 devoted as much time to the study of this 

 particular branch as any person with whom 

 I am acquainted, I take the liberty, in the 

 interest of knowledge, to ask an expression 



