218 Proceedings of the Royal Irish Academy. 



These refer to the equinoxes and solstices, as clearly pointed out by 

 the inscription, which is as follows (the lines of which run across the 

 meridian line) : — 



Gnomon Astronomicum 

 ad Certum paschalis 

 ^quinoctise Explorandum. 

 Quod S. 3Iartyr Episcopus Hyppolitus 

 Advisus est, Quod concil. I^icseain 

 Patriarchae Alexandrino, Dimandavit, 

 Quod Patres Constantienses et Late 

 ranenses, solicitos habuit. Quod inter 

 Eomanos Pontifices Gregrorius XIII 

 et Clemens XI incredibile Labore et 

 Adhibitan Peritorum Astronomorum 

 industria conati sunt. Hoc Emulator, 

 Stylus iste, cum sub Ductum Lin. meri 

 diana, puncto jSlquinoctiaU certis 

 Periodorum, — Solarium indicibus. 



On the floor between the two transepts occurs the following 

 inscription (the lines of which also run across the meridian line) : — 



Opus. D. 0. M. Sacrum, 

 elaboravit 



Scientiarum Academiae nomine et consi 

 liis C. CI. le Monnier Ejusdem Acad, et 

 London, Socius. Ad. ^quinoctise Autumnali 

 et in HiemnaH Solstitia absolvit An. 

 Eep. Sal. i MLCCXLIII. 



