1846 FIELD-WORK IN WALES 83 



staff of the Survey] to Ffestiniog, and found Sir H. 

 there with erysipelas in the leg. Jolly ! 



iotk. Came down to Bala with Sir H. and Jukes 

 in an eternal rain. Jukes and I dined with Sir H. 

 Pleasant evening, very. 



27^. Jukes and Forbes rode to the foot of the 

 Arenig ; Aveline, Williams, Gibbs, and I walked. 

 Foggy on the top. Ash, ash, ash everywhere.' By 

 this time Ramsay's eyes were fully opened to the 

 great importance of recognising the detrital material 

 of old volcanic explosions among the Palaeozoic 

 systems. Writing to W. T. Aveline on the 23rd Sep- 

 tember, he says : * On the whole, my experience here 

 makes me much more sceptical of altered rocks, 

 generally speaking, than I used to be, there being 

 many beds here that I would once have considered 

 altered rocks, which are in reality nothing but hard 

 consolidated ashes. The word " ashes " does not 

 imply " cinders," but often rather volcanic dust, which 

 may be as fine as you like.' 



' 1 8M November. Bala. Out among the traps ; 

 had a glorious find of fossils. 



igtk. Wrote Forbes with a trilobite. Away up 

 far among the traps. Got an excellent day's work 

 done. 



21.57'. Out with Aveline to the traps. It got wet 

 and turned us just when we had begun to work. 

 Nevertheless, we got a goodish day's work done on 

 the way home by the river, into which, a branch giving 

 way, I tumbled considerably over the boots.' 



One of the most important events in the progress 



joined the Geological Survey in 1846. He was appointed Director of the 

 Geological Survey of Ireland in 1850, and held that post till his death. Much 

 information about the Survey work in Wales will be found in Jukes's Letters (1871), 

 many of which were written to A. C. Ramsay. 



