INTRODUCTION. 
Xlll 
year, my acquaintance with the South of England limestone was 
renewed by an examination of part of Mendip, and the gorge of the 
Avon at Clifton ; I carefully inspected the collection of Mr. Miller 
now transferred to the Bristol Institution, the collection of the Bath 
Institution arranged by Mr. Lonsdale, the cabinets of Col. Houlton 
and the Rev. B. Richardson of Farley castle, Mr. Meade of Chatley, 
and the Rev. H. Jelly of Bath. 
In 1830, I saw again, in company with Mr. G. W. Wood, the 
limestone tracts of Namur and Luxemburg, the Museums of the Nether- 
lands, the rich and well arranged Museum of Strasburg, the public 
Collections at Geneva and Lyons, and the valuable Cabinet of M. 
De Luc. 
In 1831 my leisure was almost wholly occupied by the preliminary 
arrangements of the First Meeting of the British Association for the 
Advancement of Science ; but in the neighbourhood of Halifax I was 
enabled through Mr. C. Rawson to add materially to my knowledge 
of the lower coal system, and to demonstrate the occurrence of a 
marine (calcareous) bed with fossils of the mountain limestone among 
the coal series. 
In the summer of 1832 I surveyed the vicinity of Harrogate, the 
whole length of Nidderdale, crossed over Great Whernside, explored 
the curious districts of Kettlewelldale, and Greenhow hill, and added 
to my knowledge of other adjacent tracts. In the autumn of this 
year, Swaledale and Arkendale were reexamined ; and I measured 
every visible bed in Water crag, Lovely seat, Bear’s head. Addle- 
burgh, and many inferior hills, besides threading several glens. 
In the spring of 1833, I again visited and measured almost every scar 
in Coverdale, Waldendale, Bishopdale, Simmer water, and all the head 
branches of Yoredale; revisited Kettlewell; crossed from Askrigg to 
Muker, walked over the summit of Swaledale, to Kirby Stephen ; ex- 
amined the curious districts of Mallerstang and Ravenstonedale ; passed 
