VOL. LXIII.] PHILOSOPHICAL TRANSACTIONS. 4] 5 



water's canal, in a powdery form, and when mixed with ^ part of clay is 

 burnt to quick lime. All the above marls crack and fall to pieces when exposed 

 to the weather. 



The foregoing experiments were undertaken with a view to ascertain how far 

 it would be advisable to attempt burning the marls of this country into quick- 

 lime, for the purposes of agriculture; they may likewise furnish us with some 

 useful hints relative to the kind of marls proper to he used on different kinds of 

 lands. Perhaps the calcarious earth united with clay, as in N° ], 2, 4, &c. may 

 be the best for light sandy soil; and N° 6, Q, 10, 11, where the calcarious earth 

 is united with sand, the most eligible where the land is already stiff, and abound- 

 ing with clay. How far the different quantities of fixable air, or other volatile 

 parts, contained in each of the marls, as shown by the 3th column, will influ- 

 ence their preference in agriculture, must be left to the experience of the farmer 

 to determine. 



XX. Of a Fiery Meteor, seen Feb. lOth, 1772; and also on some New Electrical 

 Experiments. Dated Eccles, Bertvickshire. By Patrick Brydone, Esq., p. l63. 

 On Monday the 10th of Feb. 1772, exactly at 7 in the evening, as Mr. B. 

 was riding through Tweedmouth, a village at the south end of Berwick-bridge, 

 he observed that the atmosphere was suddenly illuminated in a very extraordinary 

 manner. The light of the moon, which was about half full, seemed to be ex- 

 tinguished by the blaze ; and he saw his shadow projected on the ground, and 

 almost as distinct, and well defined, as in sun- shine. He turned round to see 

 whence the light proceeded, when he beheld a long, bright flame, moving almost 

 horizontally along the heavens. It was of a conical form, and from the base to 

 the apex could not be less than 6 or 7 degrees; its height, when he first ob- 

 served it, seemed to be about 50 degrees; but it descended gently, and ap- 

 peared to burst about 5 or 6 degrees lower. Its course was from n. w. to s. e., 

 and seemed to have an inclination to the horizon ; but this might be only a 

 deception. The base of the cone was rounded like a sphere ; and apparently of 

 about -i- of the diameter of the moon at her greatest height; but its light 

 was brighter than that of the planet Venus, and in colour resembled the flame 

 of burning camphor. Near the end of the tail 

 there was a kind of waving motion, which, with 

 the whole appearance, is endeavoured to be re- - 

 presented by the annexed figure. In about 10 

 or 12 seconds it seemed to burst, dividing into a number of small luminous 

 bodies, like the stars in a sky-rocket, which immediately disappeared. 



As Mr. B. had formerly observed explosions from meteors of this kind, he had 

 presence of mind to pull out his watch, which has a 2d hand, to measure the 



