.^ 



io8 



MATHEMATICAL and 



at 2o''- 23' 



the horizontal diameter of the Sun 31^ 31^', whence the 



value of the fcale of the micrometer was determined for 



the prefent purpofc. Hence the eclipfed parts of the Sun 



were 16'. i6\ or 6 dig. 11' 562 on the northern part of 

 his difk. 



Mr. Hitchins obferved the beginning of the eclipfe with 

 a three and an half achromatic telefcope magnifying ico 

 times (the fame with which Mr. Dollond obferved the con- 

 tads of Venus) at 1 8''- 38' . 59'', and the end of the eclipfe 

 with the fix feet refledor with the magnifying power 90, 



' ■ 3S'' apparent time. And Mr. Samuel Dunn 

 obferved the beginning of the eclipfe at i 8^- 39'. 9^^, and 

 the end at 26^' 23'. 33^ with the other three and an half 

 feet achromatic telefcope, magnifying 140 times, the fame 

 with which he obferved the contads of Venus. Several 

 inequalities in the Moon's circumference, feen upon the 

 Sun's difk during the eclipfe, were diflindlly difcerned by 

 all of us, the air being very clear, and the objeds fteady. 



The whole feries of meafures of the lucid parts, which! took with the achromatic objctiil 

 glafs micrometer applied to the two feet telefcope, was as follows. 



Apparent time. I^ucid parts. 



h, m. fee, m, fee. 



19 a:j 13 — — — — jj 



24 21 — — — . — . 15 



31 44 — — — — xs 



3» 30 -^ — — — 15 



33 19 ^ — « ^ 15 



34 aS — — — — 15 



36 19 — — — — xs 



37 S^ — — — — xj 



40,5 



30,9 



15,6 



14,5 

 16,4 



16,4 

 19,8 



49a 



of the 

 1769. 



9/ the Transit o/Ve 



Mr. J 



hferved at the Lizard Point, % 



M 



R. Mafkelyne, the aftronomer-royal, who has 

 drawn up this fhort account, mentions that 

 having had fome doubts that neither the latitude nor lon- 

 gitude of the Lizard Point were duly fixed, " he had pro- 

 pofed thofe doubts to the Board of Longitude, who being 

 fenfible of the importance of determining the pofitlon of 



a place 





l\ 



/ 



