﻿ANNIVERSARY ADDRESS OF THE PRESIDENT. XXXVU 



been known by the map of Sir Richard Griffith — a rare combination 

 of geological knowledge and persevering industry for one individual 

 to have produced. But, with few exceptions, and those principally 

 in the northern part of the island, little had been known of those 

 minute details of structure which the advanced state of geology 

 requires. The required closer examination has been for some time, 

 and is now, in active progress, in conformity with a general plan ema- 

 nating from the Director-General of the Geological Survey of the 

 United Kingdom, worked out in its details under the superintend- 

 ence of Mr. Jukes, of whose eminent fitness for the task, by scientific 

 acquirements, experience in the field, and untiring energy, you are 

 well aware, — aided as he is by very competent surveyors. 



The Ordnance Map of Ireland, on the scale of 1 inch to a mile, is 

 divided into 205 squares of equal dimensions ; and each square will 

 be published as a separate sheet. Of those sheets, twenty-seven 

 geologically coloured have already been published, and twenty-one 

 are nearly ready. Each sheet (or each small group of sheets, when 

 it is advisable to unite them) will be accompanied by a printed ex- 

 planation in 8vo form, containing, first, an account of its physical 

 geography, showing the form of the ground, the heights of the chief 

 points, the mean level of its plains, and the levels at which the prin- 

 cipal rivers enter and leave, that are included in the sheet ; secondly, 

 a brief general account of the sedimentary formations and eruptive 

 rocks, with a general sketch of the internal structure ; thirdly, a 

 sketch of the relation between the form of the ground and its in- 

 ternal structure ; and fourthly, palceontological notes on the most 

 remarkable fossils. After these come " Detailed Descriptions," 

 giving an account of the observations made, the places where quarries, 

 pits, sections, &c. may be seen, and as much of the field-notes as 

 will guide any one who wishes to examine for himself and verify 

 the observations of the surveyors, together with notes of the mi- 

 nerals, mines, drift, and bogs ; and woodcut-illustrations are given 

 with the text. There are, moreover, sheets of longitudinal and 

 vertical sections, having only the observed data engraved. It is 

 further intended, when all the sheets are finished, to have condensed 

 memoirs on large districts. 



In these ' Explanations ' there is necessarily much repetition ; but 

 they contain so great an amount of valuable contributions to geo- 

 logical science in the strict meaning of the term, that, as a general 

 work, they will well reward an attentive perusal. One of the most 

 striking features described is the great extent of the surface that is 

 covered by drift, its vast thickness, and the great height at which it 

 is found in many places. 



Although not connected with the Geological Survey of the United 

 Kingdom, that now in progress in our Indian Empire is so similar 

 in its organization, that it is to be reckoned as one of the great 

 associations through which the sons of Britain are contributing 

 their share to the advancement of geological science. 



It is now ten years since Mr. Oldham, the Superintendent of the 

 Geological Survey of India, arrived in Calcutta, with the excellent 

 preparation of having been Professor of Geology in Trinity College 



