290 Eminent Living Geologists — 



Wales, first on the cleavage structure of the slates, and then on the 

 Ordovician igneous rocks. The results of the latter work were in 

 part embodied in the Sedgwick Prize Essay for 1888. 



From 1889 to 1893, excepting a visit to America, Harker's 

 vacations were spent mostly with his friend and fellow-Johnian, 

 J. E. Marr, in the Lake District. Their aim was principally to 

 decipher the geological structure and sequence of that district in 

 the light of what had been learnt in other disturbed areas. This 

 problem is perhaps not to be finally solved without a complete 

 re-survey of the ground ; but some conclusions were reached, and 

 memoirs on the Shap granite and its metamorphism and on the 

 Carrock Fell intrusions were also among the results of those 

 pleasant years. 



In 1895, by the good offices of Sir Archibald Geikie, Harker became 

 attached to the Geological Survey of Scotland, and was engaged for 

 ten years in the investigation of part of Skye and of the Small Isles 

 to the south. The summer half of the year was spent in mapping 

 and the winter half in the study of material gathered in the field. 

 The results of this work are contained in the official maps and 

 memoirs, including a special memoir on The Tertiary Igneous Hocks 

 of Skye. 



In 1905 he quitted the Geological Survey for other engagements. 

 The geological department at Cambridge was now housed in the new 

 Sedgwick Museum, and teaching duties, together with the charge of 

 the penological section of the Museum, had become more engrossing. 

 Dr. Harker found time, however, for frequent visits to the Highlands 

 and other parts of Britain with occasional excursions abroad. -He 

 had made it part of his programme as a teacher of students to bring 

 together, as far as possible, complete representative collections of 

 rock-specimens in the Museum at Cambridge, which now possesses 

 large series from many British areas, as well as from Norway, Canada, 

 and other countries. The collection of rock-slices also has grown 

 until it now numbers more than 12,000. 



Dr. Harker had written in 1895. chiefly to meet the needs of his 

 own students, a Textbook of Petrography, and this has been revised 

 from time to time in subsequent editions. In 1909 appeared The 

 Natural History of Igneous Hocks, which aimed especially at 

 interesting geologists in the genetic aspect of petrology. 



In February, 1907, on the occasion of his presenting the Murchison 

 Medal to Mr. Alfred Harker, F.R.S., Sir Archibald Geikie, then 

 President of the Geological Society, said: "The Murchison Medal 

 has been assigned to you as a testimony of the Council's appreciation 

 of the importance of your contributions to Petrographical and 

 Structural Geology. 



" You had already distinguished yourself by your studies in cleavage, 

 by the zeal and success with which you had thrown yourself into the 

 pursuit of petrographical research along those modern paths in which 

 this department of our science has been so transformed and enlarged, 

 and lastly by the skill which you had shown in the field investigation 

 of the ancient igneous rocks of North Wales and of part of the 

 Lake District. 



