part 1 ANNIVERSARY ADDRESS OF THE PRESIDENT. lv 



Oxford, and during his residence at the University came under 

 the influence of Prof. Phillips. After graduating he joined the 

 Geological Survey in 1864. He was chiefly occupied with the 

 survey of the Carboniferous rocks of North Lancashire, West 

 Yorkshire, and Westmorland, but also worked in North Wales, 

 and, previous to his retirement in 1902. was engaged in mapping 

 the rocks of South Glamorgan. He contributed to many of the 

 Survey Memoirs explanatory of the geological maps, and also wrote 

 a memoir on the Water- Supply of Oxfordshire. 



He was elected a Fellow of this Society in 1869, and served on 

 the Council from 1905 to 1910. In 1911 the Council awarded 

 to him the Murehison Medal in recognition of his original contri- 

 butions to our science. His election to the Presidency of the 

 Yorkshire Geological Society in 1914 was a fitting recognition of 

 all that he had done for Yorkshire geology and geologists. He 

 had married in 1S89 Margaret Florence, younger daughter of 

 W. H. Spencer, M.D., of St. Leonard's-on-Sea, by whom he had 

 two daughters. He died on February 20th, 1917, aged 7-3. 



Tiddeman' s contributions to geological literature are not volu- 

 urinous, for he was reluctant to publish his results until he had 

 fully satisfied himself of their accuracy. What he did publish is of 

 high value, and throws much light on various geological problems. 

 In addition to his official work, he wrote a series of papers on four 

 subjects of great interest : the evidence for an ice-sheet in Xorth 

 Lancashire and its neighbourhood ; the problems of the Victoria 

 Cave at Settle ; the remarkable structures in the Lower Carboni- 

 ferous rocks of West Yorkshire which he designated ' reef -knolls ' ; 

 and the pre- Glacial raised beach of the South Welsh coast. 



The memoir on the Xorth Lancashire Ice-Sheet, published 

 in the Quarterly Journal of the Geological Society in 1872, is a 

 record of high importance, and was tersely described hj Carvill 

 Lewis as 'an admirable paper, all of which is true.' The series of 

 reports and papers on the Victoria Cave attracted much attention 

 at the time of their appearance, on account of the occurrence of a 

 supposed human fibula in a deposit claimed as anterior to the last 

 occupation of the district by ice. Tiddeman was in no way re- 

 sponsible for the erroneous determination of the bone : his own 

 work had reference to the relationship of the various deposits of 

 the cavern. The origin of the remarkable ' reef -knolls ' is not vet 

 decided. To Tiddeman is due the credit of discovering their nature 

 and recording numerous important facts connected with them. 



