8 Scientific Proceedings, Royal Dublin Society. 



suggested by the author, is the examination of the outcrop of the 

 beds, " where the exposure of the surface of the rock during ages 

 may give some indication of its power of resistance to decomposi- 

 tion ; and the examination of stones in old structures." He 

 specially points out the examination of stones in monoliths and 

 tombstones : " There could hardly be devised a better method for 

 thoroughly testing, by natural means, the durability of the stone, 

 than by its erection in this way, with partial insertion in the moist 

 earth, complete exposure to the wind, rain, and sun, on every side, 

 its bedding-lamination standing on edge, and several of its surfaces 

 smoothed and polished, and sharply incised with dates, inscriptions, 

 and carvings, by which to detect and to measure the character and 

 extent of the decay." 



As to the seasoning of stones, it is recorded that Vitruvius 

 recommended it 2000 years ago, and that it has " been observed at 

 times down to the days of Sir Christopher Wren, who would not 

 accept the stone which he proposed to use in St. Paul's cathedral, 

 in London, until it had lain for three years seasoning on the sea- 

 shore. Since then little or no attention appears to have been paid 

 to this important requirement by modern architects, in the heed- 

 less haste of the energy of the times. Building-stone, even for 

 many notable edifices, is hurried from the quarries into its position 

 in masonry long before the ' quarry sap ' has been permitted, by 

 its evaporation, to produce solid cementation in the interstices of 

 the stone." 



The pernicious effect of placing stones on their edges, and not 

 on their bed-surfaces, is also mentioned, and the carelessness with 

 which stones are selected and used. 



While pointing out the effect of the different denudants on 

 stone, it is mentioned by Dr. Julien that no material differences 

 were remarked by him in graveyards near the sea and in those 

 away from it. It seems, however, to be otherwise in Ireland, as 

 the sandstones, slates, limestones, granite, &c, on the coasts of 

 Cork, Kerry, Clare, and Gralway, are recorded as having weathered 

 more and differently from those inland (g. s. m.). Heat has a con- 

 siderable effect, as stones exposed to the sun are more weathered 

 than those which are constantly in the shade. Lichens do not 

 seem to have much effect, as, " on their removal, the surface of 

 the stone beneath is not found corroded ; it only retains a fresh 



