iif4 PHILOSOPHICAL TRANSACTIONS. [aNNO 1738. 



the eclipse was annular in those places or not. Fort Augustus is at the west 

 end of Lochness, and probably was not far from the northern limit of this 

 phenomenon. 



Several gentlemen of very good credit, who are not in the least short-sighted, 

 assure Mr. M. that about the middle of the annular appearance, they were not 

 able to discern the moon on the sun, when they looked without a smoked glass, 

 or something equivalent, 



Mr. Maclaurin remarks this, because it may contribute to account for what 

 at first sight appears surprising, that there are so few annular eclipses in the lists 

 collected by authors. Kepler, in his Astron. Optic, does not seem to acknow- 

 ledge, that any eclipse, truly annular, had ever been observed. There are none 

 mentioned by Ricciolus, from the year 334 till 1567, though there are 13 or 14 

 total eclipses recorded within that period ; yet it is allowed, that the extent and 

 duration of the annular appearance may be considerably greater in the former, 

 than of the darkness in the latter. It may have contributed to this, that annular 

 eclipses must have been rather incident in the winter season in the northern 

 hemisphere, and that eclipses have been more readily total in the summer, when 

 their chance of being visible was greater, and the season more favourable for 

 observing them. But perhaps the chief reason why few annular eclipses appear 

 upon record, is, that they have not been distinguished in most cases from ordi- 

 nary partial ones. The darkness distinguished total eclipses, or such as were 

 very nearly total ; and it is these chiefly, that historians mention. There are 

 two central eclipses of the sun still famous among the populace in this country : 

 that of March 29, l652, was total here, and that day is known among them 

 by the appellation of Mirk Monday. The memory of the eclipse of Feb. 25, 

 1598, is also preserved among them, and that day they term, in their way. 

 Black Saturday. There is a tradition, that some persons in the north lost their 

 way in the time of this eclipse, and perished in the snow. 



There was a remarkable total eclipse of the sun in this country, June 1 7, 

 1433, the memory of which is now lost among the populace; but it appears 

 from a passage in a manuscript in our library, that it was formerly called by 

 them the Black Hour, after their usual manner. It is described thus : " Hoc 

 anno fuit mirabilis Eclipsis Solis, 17""° die mensis Junii, hora quasi tertia post 

 meridiem ; et per dimidium horae tenebrae tanquam in nocte supergressas sunt 

 superficiem terrae, ita ut nihil obtutibus humanis pervium fuit ; unde abhinc 

 vulgariter dicta fuit hora nigra." This eclipse is not in Ricciolus's Catalogue, 

 but is mentioned by him in another place, Schol. cap. 2, 1. 5. By a computa- 

 tion of this eclipse, the sun was within 2° of his apogeum, and the moon with- 

 in 13" of her perigeum ; so that this must have been a remarkable eclipse. 



