Professor J. W. Judcl, CB. 387 



geological studies of the county which he had already commenced. 

 The result of these labours was seen in two noteworthy additions to 

 geological knowledge. In the first place, he was able to show that 

 the strata M'hich form the base of the Lincolnshire Wolds — which 

 had been vaguely referred either to the Jurassic or the Lower 

 Greensand — are really representatives of the Neocomian of the 

 Continent, and an examination of the Speeton Clay of Yorkshire 

 proved that all the zones shown to exist in Lincolnshire are present 

 there also under different mineral conditions. In the second place, 

 a study of the fossils in the great belt of oolitic limestones running 

 north and south through the county of Lincoln, and continued south- 

 wards into the Midlands and northward into the East Riding of 

 Yorkshire, demonstrated that these rocks are of Inferior Oolite age, 

 and not Great Oolite, as had hitherto been supposed. His work in 

 Lincolnshire was vai'ied by trips to the Continent, where, with 

 knapsack on back, he visited and studied the various equivalents of 

 the Lincolnshire strata. 



Among those who were specially interested in the results of this 

 work was the amiable Oxford professor, John Phillips. Phillips 

 made the suggestion that Judd should complete a geological map and 

 memoir on Lincolnshire, as he had himself done for Yorkshire. But, 

 on the other hand. Professor Ramsay urged Judd to accept a temporary 

 post on the Geological Survey, promising him the opportunity of 

 surveying the districts south of Lincolnshire, where his previous 

 expei'ience would be of special use. He accordingly joined the 

 Survey in 1867, and for four years was engaged in the survey of 

 Rutland and parts of the adjoining counties. The result of this 

 work was to demonstrate the necessity of a revision of the whole 

 of the Lower Oolites of the Midland districts as far south as Oxford- 

 shire and Gloucestershire. Over the whole of this area the rocks 

 hitherto mapped as Great Oolite were re-mapped as " Lincolnshire 

 Limestone" and "Northampton Sand," and placed in the Inferior 

 Oolite, while the limits and divisions of the true Great Oolite were 

 defined. During this period Judd was able to apply the methods 

 which had been taught him by Sorby to the investigation of the 

 nature and origin of the ferruginous rocks of the Northampton 

 Sand. His paper on the subject, containing a full discussion of the 

 microscopical and chemical characters of the rocks, was read before 

 the Geological Society in March, 1869, but was withdrawn in con- 

 sequence of a new regulation being made that such papers must 

 appear in the Survey Memoirs. It was at last published, but without 

 figures, in 1875. 



A former colleague and fellow- worker on the Geological Survey 

 for many years writes of his work as follows : — 



"Professor Judd joined the staff of the Geological Survey in 1867, 

 and was occupied during three years in the county of Rutland and 

 bordering portions of Leicestershire, Lincolnshire, and Northampton- 

 shire, that are included in Sheet 64 of the old series map. 



"In the course of his investigations he proved beyond question 

 that the important group of limestones which form ' the cliff ' of 



