rOL. XVI.] PHILOSOPHICAL TKANSACTfONS. 33/ 



ness, that not a quarter of a minute or 15 seconds can be wanting, and per- 

 formed both by day and night. The contrivance consists in making a very large 

 horizontal dial, adapted to the latitude of the place where the observation is to 

 be made, capable of receiving divisions into minutes, and parts of a minute, 

 fitted with a large, strong, and double gnomon. This dial is furnished with 2 

 pair of sights, one to serve in the morning, or for stars on the eastern side of 

 the meridian ; the other to serve in the afternoon, or for stars on the western side 

 of the meridian. Each of these consists of 2 moveable rulers : one called the 

 horizontal ruler, the other the gnomonic or stile ruler. These 2 rulers are so 

 adapted, that their 2 edges, which are next to the gnomon, may be perpetually 

 in the same plane with their correspondent edge of the gnomon. On the stile 

 ruler are set telescopic sights, with cross-hairs in their due place. As to the 

 manner of observing the time after the dial is justly levelled and stated ; this is 

 to be done by looking at the sun through the telescopic or stile ruler, and 

 bringing the mensurator on the sun's centre ; then the horizontal ruler will cut 

 the hour, minute, and part of a minute most exactly in the dial. By the same 

 telescopic sight, the motion of the sun will be perceived so quick and exact, 

 that 2 beats of a second pendulum may be determined, and the time of the day 

 or night to 3, 5, or 7 seconds discerned. The way of using this dial on the 

 stars by night is much the same, only that for these are requisite certain tables of 

 the sun and stars' temporary right ascensions ; for in looking at a star through 

 the telescopic ruler, the horizontal ruler cuts the star's horary distance from the 

 meridian, to which adding the star's right ascension, and from the sum sub- 

 tracting the sun's right ascension, the remainder gives the hour, minute, and 

 second of the night. 



A Table showing the Time of High Water on the Coasts, and in the Ports of 

 France, on the Day of the new and full Moon. Taken from the French 

 Ephemerides called La Connoissance des Temps, for the Year l687. N° 185, 

 p. 220. 



The times of high water on the coasts are now much more accurately set 

 down in all treatises on navigation, and other books. 



The verbal Process on the Discovery of an Ancient Sepulchre, in the Pillage of 

 Cocherel on the River Eure in France. Communicated by Mr. Justell, R.S.S. 

 N° 185, p. 221. 



This ancient sepulchre was discovered in l685 by digging for stone. It was 

 covered and inclosed by some large stones. In it were found the bones of about 



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