M, DE Zach's Ajlronomkal Objervatlons. 



143 



Father le Fevre's obfervations with a refle(n:or k,c^ niches 

 focal length, magnltynig 300 times. 



I ]M M E R s I o N s. 

 Grimaldi touches the fliadow 

 Kepler touches the ftiadow' 

 all in the fliadow 



Copernicus touches the fliadow 

 all in the fliadow 



Mare Serenitatis touches the lliadow 

 all in the fliadow 



Mare Crifiam touches the fliadow 

 . — . all in the fliadow 



Total immerlion 



EMERSIONS. 

 Beginning of theeraerfion 

 Grimaldi emerged 

 Kepler all out of the fliadow 

 Copernicus all out 

 Mare Serenitatis all out 

 Crifium all out 



End of the eclipfe 

 Total duration 



The oblervatlon of the vernal equinox was made at the 

 gnomon. The height of this gnomon, taken- from the center 

 of the hole by which the beams of the fun come in, is 1878 

 lines of a French inch ; the diftance from the bottom of the 

 gnomon to the equinoctial point is 1928 ; the diftance from the 

 upper limb of the, fun's image to the equinodlial point was 

 found 16,7 ; the diftance from the under limb 23,4 ; the dia- 

 meter of the hole = 6 ; therefore the diftance from the bottom 

 to the upper limbi 928 - 16,7 + 3 - 1914,3, to the under limb 

 1928 + 23,4-3=1948,4; which gives the time the equi* 

 uox happened the 20th of March, 5 h. 56' 52'' P.M. 



4 Obfervations 



