102 



MR. AIRY ON THE LAWS OF THE TIDES 



Upon inspecting these numbers, one law cannot fail to occur to us, namely, that 

 the irregularities are nearly the same in magnitude and in sign on every part of the 

 coast of Ireland at the same time. So prevalent is this law, tiiat there are few instances 

 in which the irregularity at one place differs from the mean of the irregularities at all 

 the places at the same time by more than an inch. My ideas of the almost perfect 

 fluidity of water have been very much raised by this comparison. I may remark that 

 it embodies, in a form admitting of easy examination, the result concluded from rough 

 inspection of observations which is made the foundation of a method for supplying 

 deficient observations described in page 10. I may also add that it gives no small 

 security for the general fidelity and accuracy of the observers at the different stations. 



I do not perceive any certain connexion between the irregularities and the course of 

 the winds, except that the water is usually highest on all parts of the coast with a 

 violent south-west wind. 



In order to ascertain the general relation of these irregularities to those of the 

 barometer, I have compared the corrected mean height of the barometer at Green- 

 wich for each civil day with the mean height for the year (using the numbers pub- 

 lished in the Greenwich Magnetical and Meteorological Observations). The follow- 

 ing are the results : — 



I have also obtained, through the kindness of Sir W. R. Hamilton, the barometrical 

 observations at the Observatory of Dunsink, near Dublin ; and from Colonel Colby 

 and Captain Larcom, R.E., I have received the observations made in the Phoenix 

 Park near Dublin, and at Limerick. The following results are obtained by com- 

 paring each day's mean with the mean for this period. 



