Additions and corrections

Abstract Page 99, line 5 ,for Protagoras, read Protogenes 186, last line, for southerly, read northerly 204, line 4 , for heat, read iodine 272, line 17, for about io°, read between 12° and 14* 275, line 18, for 39º, read 37º 30' 277, line 17, for nearly 1/200 read less than 1/820 Id. lines 21 and 23, for 141°, read 141º 53'