21 



great elevations, where the reaction is very minute^ only two 

 fluctuations would be found in the day : the maximum at 

 about two o'clock, p. m., when most air would be above the 

 barometer; and the minimum at daylight in the morning, 

 when least air would be above it ; but I know of no observa- 

 tions to confirm or refute these deductions." 



Mr. Ball brought under the notice of the Academy the 

 fact, that the ordinary sturgeon of the Dublin markets is an 

 undescribed species. He stated that Mr. Thompson of Bel- 

 fast, and Professor Agassiz, concurred with him in this opi- 

 nion, and he proposed to call it Accipenser Thom.'psoni, pur- 

 posing, if permitted, to give figures and full descriptions in a 

 future number of the Proceedings. 



A notice of an unpublished Irish coin of Edward IV. was 

 read by A. Smith, M.D., M.R.I. A. 



" Within the last month some workmen were employed 

 in cleaning one of the city drains in the Cross Poddle, and a 

 few coins were found. Among them was one of no intrinsic 

 value, and apparently of no interest whatever. It is made of 

 brass, and was originally plated with silver, traces of which 

 still remain. On one side it has a crown within a circle of 

 pellets, outside which, in place of a legend, are crosses and 

 roses alternately ; on the other side it has the common type — 

 a cross, with three pellets in each quarter'; the legend is de- 

 faced. It weighs nearly five grains, and is now in the cabinet 

 of Lieutenant-Colonel Weld Hartstonge. 



" This little coin bears no evidence in itself which would 

 enable us to say to what king's reign it should be appropriated, 

 or even to what country. But on referring to an Act passed 

 in the second year of Edward IV., at a parHament held in 

 Dublin, we find it enacted, ' that a coyne of copper mixed 

 with silver, be made within the Castle of Dublin, having on 

 one side the print of a cross, and on the other part a crown, of 

 which four shall be taken for a penny ; and that the said 



