THE 



SCIENTIFIC PEOCEEDINGS 



OF THE 



ROYAL DUBLIN SOCIETY. 



Vol. III. (New Series). JANUARY, 1881. Part I. 



CONTENTS. 



Page 



I. On a Xew Form of Ghost Micrometer for use with Astro- 

 nomical Telescopes. By Chas. E. Bueton, F.Ii.A.S., and 

 Howard Grubb, F.R.A.S. Plates 1, 2, 3, and 4, . . 1 



II. On a Travertine from Ballisodare, near Sligo, containing a 

 considerable amount of Strontium. By Edward T. Hardman, 

 F.C.S., 12 



III. Preliminary Note on the Manufacture of Paper from Molinia 



coerulea. By W. Smith, 14 



IV. Notes on some New or Bare Irish Hepaticae. By David 



M'Abdxe. Plates 5 and 6, 17 



V. North- American Birds crossing the Atlantic. By Percy 



Evans Feeke, 22 



The Authors alone are responsible Jbr all opinions evprtssed in their communis 



l(io(]S(\ Nluse;> :,. 



DUBLIN: 



PUBLISHED BY THE ROYAL DUBLIN SOCIETY. 

 PRINTED BY ALEX. THOM & CO., 87, 88, & 89, ABBEY-STREET, 



THE queen's printing OFFICE. 

 FOR HER MAJESTY'S STATIONERY OFFICE. 



1881. 



