447 



delineation of a tract of country around Ludlow, which, from repeated 

 personal examination, I can testify to be a model of accuracy. 



Mr. Maclauchlan, another of our Fellows, attached to the Ord- 

 nance Survey, has with equal success illuminated a much larger 

 surface of the Ordnance maps, comprehending the Forest of Dean, and 

 the central parts of Herefordshire. His details respecting the rich 

 coal-field in the Forest of Dean are of singular value, being de- 

 rived from the observations of so experienced a miner as Mr. 

 Mushett. 



Our Society has further been most advantageously connected with 

 the Ordnance Survey, by the appointment of Mr. De la Beche to 

 affix geological colours to the maps of Devonshire, and portions of 

 Somerset, Dorset, and Cornwall. From our acquaintance with the 

 skill of this geologist, and from his long practice in the districts which 

 he has undertaken to represent, it is certain that he will furnish many 

 striking examples of the value of well-defined physical features, in 

 enabling the geologist to explain the relation of the present outline 

 of the land to ancient subterranean movements. 



The adoption of a fixed scale of colours by all English geologists 

 is still an essential desideratum in this department; and I am happy 

 to have it in my power to state, that a systematic arrangement 

 will shortly be submitted to you, after it has undergone the super- 

 vision of our Council, and shall have met with the approval of the 

 Board of Ordnance. This scale, being founded on the principle of 

 employing such colours only as are fixed and distinct from each other, 

 has been suggested by our valued member Mr. Chantrey, who, by 

 this highly useful appropriation of his leisure moments, has aug- 

 mented those claims upon our gratitude which he had established by 

 many acts of good fellowship, and the devotion of his time and talents 

 to our cause. 



Through the early investigations of William Smith, the oolitic series 

 was divided into sub-formations ; and, by the subsequent adoption of 

 these subdivisions by Conybeare, their provincial names have become 

 classic throughout Europe, and have served to commemorate the 

 discernment of him who first taught us to identify strata by their 

 organic remains. 



At the last anniversary it was announced that, with entire confi- 

 dence in his qualifications, your Council had fixed upon Mr. Lons- 

 dale to commence a task, the prosecution of which they conceived 

 to be strictly consonant to the spirit of the bequest of the lamented 

 Wollaston ; by which we are endowed with the means of rewarding 

 those who enlarge the circle of geological knowledge. Mr. Lonsdale 

 has presented us with the result of his labours, having laid down upon 

 maps of the Ordnance Survey the range of different members of the 

 oolite, from the neighbourhood of Bath, where he had previously de- 

 veloped their relations, to the southern limits of Warwickshire and 

 Oxfordshire. The success attendant upon this undertaking has already 

 been made apparent in the maps, sections, and remarks of our Curator. 

 By these you will perceive he has already demonstrated that the upper 

 shale and marl-stone of the lias, which are only visible as mere beds 



