Royal Irish Academy. 395 



Mr. Dirt's book no mention is made of a depository for the observations 

 he wishes made ; but possibly he is wilHng to receive and reduce 

 them himself, and to publish their results. Some such guarantee as 

 this is needed, or we cannot expect gentlemen to engage in long 

 and tedious series of observations. 



The fourth section speaks of periods of extra observations, and par- 

 ticularly of that of the great atmospheric wave of November. Our 

 experience does not confirm the existence of this particular wave. It 

 seems to us that waves as regular and as large take place in the pre- 

 ceding and following months ; and therefore^ that if this period be 

 made one of special investigation, it ought to be extended so as to 

 include the months of October and December. 



There is an appendix to the work, being a reprint of Tables I. and 

 II. from the Report of the Committee of Physics of the Royal Society 

 for the reduction of the readings of those barometei's whose scales 

 are of brass, extending from the centre to the top of the mercurial 

 column. 



The discussion of simultaneous observations of the barometer, and 

 directions of the wind, have already led to unexpected rules to 

 guide the mariner, to whose notice we recommend this work. 



L. Proceedings of Learned Societies. 



ROYAL IRISH ACADEMY. 



AT the last meeting of the Royal Irish Academy, the Rev. Dr. 

 Lloyd, D.D., the President, made the following observations on 

 the recent destructive storm in Dublin : — 



" Having watched attentively the progress of the late storm, and 

 collected some facts relative to it from the records of the observatory, 

 and from other sources, I avail myself of the present opportunity to 

 lay them before the Academy. The pheenomena were of a nature so 

 unusual (I may say unexampled) in these climates, that it is desi- 

 rable that some notice of them, however imperfect, should be placed 

 on record, aud the present summary of facts is offered chiefly in the 

 hope that it may serve as a nucleus to a more complete one. I shall, 

 of course, limit myself to those which have an immediate scientific 

 bearing. 



" From the tracings of the self- registering anemometer erected in 

 Trinity College, it appears that on the 17th, and during the morning 

 of the 18th, the wind blew gently from the S.W. Towards noon, 

 on the latter day, it gradually veered to the S., and continued at 

 that point until the arrival of the storm. This veering of the wind, 

 however, appears to have been confined to the lower current. The 

 direction of the upper current, as estimated by the motion of the 

 clouds, was nearly S.W. 



" The first indications of the approach of the storm were observed 

 soon after three o'clock. Massive cumuli were seen forming in the 

 south-western portion of the sky. These became denser as they 

 approached, until they formed a mass of an ash-gray colour, pro- 



2D2 



