284 



Proceedings of the Royal Irish Academy. 



3. 1th July, 1879. — Observed by Dr. Macalister and self, using 

 single readings of one index : — 



11 



e 



Combination. 



I 



7 







ior-25 







1 



87-50 







2 



75 -50 







3 



65 -00 







4 



55 -00 







6 



48 -75 





1 



313-1 



6 



41 -25 



(0,6) 



7 



35 -75 







8 



29 -50 







9 



26 -75 







10 



22 -50 







11 



18 -50 







12 



17 -GO 





1 



13 



15 -00 



(0, 13) 



318-9 





Mean, . . . . 



■^ 3160 





4. %th July, 1879. — Observed by Dr. Macalister and self, using 

 double readings with both indices : — 









Combination. 



1 









/ 







102°-125 







1 



87 -875 



(0, 1) 



311-7 



2 



75 -375 



(0, 2) 



308-5 



3 



64 -750 



(0, 3) 



308-5 



4 



56 -000 



(0, 4) 



311-9 



5 



47 -875 



(0, 5) 



309-2 



. 6 



41 -625 



(0, 6) 



313-2 



^7 



35 -750 



(0, 7) 



312-5 



8 



30 -750 



(0, 8) 



312-3 



9 



26 -375 



(0, 9) 



311-5 



10 



22 -750 



(0, 10) 



312-0 



Mean, . 



. . . 311-13 + 0-37 (mean probal 



)le error). 



