272 PHILOSOPHICAL TRANSACTIONS. [aNNO 1746. 



without sufficient reason. But Mr. Huygens, having more accurately examined 

 the matter, found it to be the best temperature that could be contrived. Though 

 neither this great mathematician, nor Zarlino, Salinas, nor even Don Vincentino, 

 seems to have had a distinct notion of all these 3 1 intervals, nor of their names, 

 nor of their necessity to the perfection of music. 



In Huygens's temperature the tones are all equal ; but in a true and accurate 

 practice of singing they are not so. And the tone divided in every species must 

 be the tone minor; for the division of the tone major is harsh and inelegant. 

 So that, in the division of the 4th, it is to be observed, that in every species, 

 the tone major must either be an undivided interval, or make part of one. 



It may perhaps be wondered how the foregoing doctrine can be found in the 

 writings of the ancients, since the distinction of tones into major and minor is 

 no where mentioned in them. But it is to be observed, that though the terms 

 do not occur, yet the thing itself was not unknown to them. They have not 

 indeed expressed themselves fully; yet, from the whole of their writings come 

 to our hands, the doctrine before laid down may be well supported. 



Observations on the Precipices or Cliffs on the North-east Sea Coast of the 

 County of Norfolk. By Mr. Wm. Arderon, F. R. S. N° 481, p. 275. 



These dreadful heights are equally dangerous to come near above or below; as 

 they are so frequently tumbling down, and as often washed away by the billows ; 

 and though they are 20, 30, and in some places 40 yards, or more, in perpendi- 

 cular altitude, yet the sea has gained on the land at least 110 yards in less than 

 20 years time for some miles on this coast. 



The various strata, which make up this long chain of mountainous clifFs, 

 must be very entertaining to every one, who takes a pleasure in looking into the 

 many changes which the earth undoubtedly has undergone, since its first crea- 

 tion. Vegetable mould, oaz, sands of various kinds and colours, clays, loams, 

 flints, marls, chalk, pebbles, &c. are here to be seen at one view beautifully in 

 terspered; and frequently the same kind many times repeated; as if at one time 

 dry land had been the surface; then the sea; after morassy ground; then the 

 sea, and so on, till these clifFs were raised to the height they are now found. 



This is demonstrated by the * roots and trunks of trees, which are to be seen 

 at low water in several places on this coast near Hasborough and Walket ; bones 

 of animals are often found here also. 



Among the many strata found in these clifFs, there is one of a dark grey co- 

 lour, that sweats out a yellow sulphureous matter; it seems to be that sort of 



* Dr. Hook, in his posthumous works says, the like are to be seen on the coasts of Cunjberland 

 and Pembrokeshire. — Orig. 



