38 Doubts and Facts concerning Linne. 



find the value in seconds of arc of the estimations on the one 

 hand, and in English feet of the measures on the other. From 



the data 



given, the following table has been constructed : 



ESTIMATIONS AND MEASURES OP THE EXTENT OP LINNE. 



Authority. 



Epoch. 



Eng. feet. 





Objects. 



Remarks. 



Schmidt .... 

 B. and M.... 

 Schmidt .... 

 Birt 



1831 



1866, Oct. 18 

 1866, Dec. 15 

 1866, „ 18 

 1866, „ 19 

 1866, „ 21 



1866, „ 27 



1867, Jan. 14 

 1867, Mar. 14 

 1867, June 12 

 1867, July 8 

 1867, „ 9 

 1867, „ 10 

 1866, Dec. 13 



1866, „ 26 



1867, Jan. 25 

 1867, „ 25 

 1867, Feb. 11 

 1867,Apr,,May 

 1867, June 12 



36,449 



33,482 



48,688 



81,920 



49,886 



51,650 



47,627 



12.790 



56,100 



42,336 



31,752 



37,623 



49,420 



37,845 



1918-4 



1695 



1279 



1918-4 



2352 



28,224 



7056 



5-17 

 4-83 

 690 

 11-61 

 707 

 732 

 6-75 

 1-81 

 7-95 

 600 

 4-50 

 5-33 

 7-00 

 5-36 

 027 

 0-24 

 018 

 0-27 

 0-33 

 4-00 

 100 



Crater 

 Crater 



Whitish cloud 

 Whitish cloud 

 Whitish cloud 

 Whitish cloud 

 Whitish cloud 

 Whitish cloud 

 Whitish cloud 

 Whitish, cloud 

 Whitish cloud 

 Whitish cloud 

 Whitish cloud 

 Whitish cloud 

 Delicate hill 

 Fine black point 

 Fine black point 

 Fine white peak 

 Small crater 

 Small crater 

 Small crater 



Measured 

 Measured 

 Measured 

 Measured 



Measured 

 Measured 



Measured 

 Measured 

 Measured 



95 

 »J 



55 



Birt 



Buckingham 

 Wolf 



Birt 



5» 



5J 



55 



55 



Eespighi .... 

 Wolf 





This table furnishes three sets of numbers : first, the 

 diameter of the crater in 1831, and about that epoch ; second, 

 the estimations and measures of the whitish cloud, in which 

 there are considerable variations ; and third, the estimations of 

 the small crater. Under this head the most serious difference 

 is that between Secchi and Eespighi. 



It would be highly improper to question for a moment the 

 estimation of Respighi. The difference, however, between his 

 estimation and that of Secchi, of nearly 26,000 English feet, 

 calls for some remark. Respighv's observations were made with 

 great care, and it is probable that he might have seen an 

 opening which he estimated at that diameter, especially as the 

 small crater was seen with greater distinctness in April. The 

 diameter of this opening may, from some cause or other, not 

 have been permanent in its extent. I am quite satisfied, that 

 with the Royal Society's refractor of 4| in. aperture (Respighi's 

 was 4s French inches aperture) I could have seen and mea- 

 sured a crater of 4"*0 in diameter; in fact, I have many 

 smaller on the British Association outline map, which I have 

 not only seen, but discovered with the 4} inch aperture, power 



