16 Mr.Witham on the Vegetable Fossilsfound at Lemiel Braes, 



the heat of the sun upon his circle. Still, however, by means 

 of equations, which give the necessary corrections attributable 

 to this cause, he renders them nearly equal. It is generally 

 understood that the Palermo circle made by the late Mr. 

 Ramsden is very liable to be acted upon by heat during the 

 time of observation, while that of Greenwich is much less so, 

 or not very sensibly. 



No doubt this may be one of the causes of discrepancy in 

 others, and almost the sole cause in his, since it is very liable 

 to alter its form by heat; but in more northerly latitudes it per- 

 haps may be doubted whether this is the true cause, more 

 especially as an adequate one, depending upon a different 

 principle, has just now been produced. 



I am, Gentlemen, yours &c. 

 Edinburgh, April 24, 1830. WlLIJAM GaLBRAITH. 



III. On the Vegetable Fossils found at Lennel Braes, near 

 Coldstream, upon the Banks of the River Tweed in Berwick- 

 shire. By Henry Witham, of Lartington, F.G.S. fyc.* 



X_TAVING been requested by several gentlemen to present 

 -*--*- to the public a statement of facts, respecting the fossil 

 Flora in the neighbourhood of Coldstream, upon the banks of 

 the river Tweed, I feel confident you will allow this paper a 

 place in your valuable publication. 



As the fossil vegetable kingdom has been divided into four 

 great groups or periods, and as M. Adolphe Brongniart is of 

 opinion that the transition is abrupt, and that there is a sud- 

 den difference in the most important characters of the vege- 

 tables, it becomes necessary for me to divide this memoir un- 

 der three heads. 



1st A description of the surrounding strata. 



2ndly. A description of the fossil plants themselves, with 

 their position ; and, 



Srdly. A few observations upon both these heads. 



1st. It has long been matter of dispute under what class of 

 rocks the deposits in the neighbourhood of Coldstream are to 

 be described. Some are of opinion that they are members of the 

 old red sandstone series ; and others, that they are to be classed 

 with a much more recent deposit, the new red sandstone. 



The following facts, which have been taken with great ac- 

 curacy by my intelligent friend Mr. Francis Forster and my- 

 self, will I trust set this question at rest. — Immediately below 

 the bridge at Coldstream, at its south end, you perceive a bed 



* Communicated by the Author. 



of 



