86 Memoir relative to the Annular Eclipse of the Sun, 



\7'iS*; the former of which was observed by the celebrated 

 Colin Maclaurin at Edinburgh, and the latter by the Earl of 

 Morton and Mr. Short at Aberdour Castle near the same place. 

 Indeed the annular appearance of the eclipse of 1737 was con- 

 fined principally to Scotland : and the eclipses of 1748 and 1764, 

 although visible to a great part of Europe, were not so generally 

 observed as could be wished on account of the badness of the 

 weather ; so that we have not anv very considerable degree of 

 information respecting this kind of solar eclipses. Moreover at 

 those periods the lunar tables were so defective that it could no? 

 be predicted, with any degree of accuracy, where the annular 

 appearance would be visible : so that many valuable observations 

 were probably lost on that account. This difficulty however is 

 in a great measure removed by late improvements not only in 

 the lunar tables, but likewise in the analytical investigations re- 

 lative to the calculation of eclipses; although the computations 

 are still very laborious and troublesome. 



Prior to the total eclipse, which took place in London in the 

 year 1715, Dr. Halley published an account of the path of the 

 moon's shadow across the island of Great Britain; and called 

 on the inhabitants to note down their observations and forward 

 them to him, in order that he might afterwards compare them, 

 and thereby correct the elements made use of in the calculation 

 of eclipses. The good effect of this measure mav be seen in the 

 Report which that illustrious astronomer afterwards drew up and 

 sent to the Royal Society, and which is inserted in the Philoso- 

 phical Transactions, No. 343, vol. xxix. page 245. Mr. Mac- 

 laurin, likewise, previous to the annular eclipse in 1737 before 

 mentioned, wrote to several persons in the country, " desiring 

 that they would determine and note down the duration of the 

 annular appearance as exactly as possible; in hopes, by com- 

 paring their observations, to have traced more correctly the path 

 of the centre and limits of the phaenomenon." And in 1748 

 Mr. Alexander Munro (Professor of Anatomy of Edinburgh) by 

 Mr. Short's desire wrote to all his friends in different parts of the 

 country, to prepare in the best manner they could for the most 

 exact observation of the annular eclipse which was about to take 

 place in that year. And he regrets that he did not make this 

 application earlier ; for he remarks that had " my request of having 

 the duration of the annular appearance nieasured been made more 

 public before the eclipse (after Dr. Halley's example in 1715) I 

 doubt not but I should have been able to have given a more exact 



• See a detailed account of these eclipses, and of the phaenomena attend- 

 ing them, in the Philosophical Transactions, vol. xl, page 1 77, and vol. xlv, 

 page 582. i • 



' ^ccounli 



