SCIENTIFIC PROCEEDINGS 



OF THE 



ROYAL DUBLIN SOCIETY. 



701. X. (I. S.) NOVEMBER, 1904. Part 2. 



CONTENTS. 



PAGB 



XI. — Floating- Refracting Telescope. By Sir Howard Grubb, 

 F.R.S., Vice-President, Royal Dublin Society. (Plates 

 VII.-1X.), 133 



XII. — Registration of Star-transits by Photography. By Sir Howard 



Grubb, F.R.S., Vice-President, Royal Dublin Society, . 138 



XIII. — A New Form of Diple'ioscope. By Sir Howard Grubb, F.R.S., 



Yice-President, Royal Dublin Society. (Plate X.), . . 141 



XIV. — A Circumferentor. By Sir Howard Grubb, F.R.S., Vice- 

 President, Royal Dublin Society. (Plate XL), . . .143 



XV. — A New Form of Position- finder for adaptation to Ship's Com- 

 passes. By Sir Howard Grubb, F.R.S., Vice-President, 

 Royal Dublin Society. (Plate XII.), .... 146 



XVI. — An Improved Simple Form of Potometer. By G. H. 



Pethybridge, Ph.D., B.Sc, 149 



XVII. — Willow Canker : Physalospora [Botryosphceria) gregaria, 

 Sacc. By T. Johnson, D.Sc, F.L.S., Professor of Botany 

 in the Royal College of Science, and Keeper of the Botanical 

 Collections, National Museum, Dublin. (Plates XIII.-XV.), 153 



XVIII. — The Comparison of Capacities in Electrical Work : an Appli- 

 cation of Radio-active Substances. By J. A. McClelland, 

 M.A., Professor of Experimental Physics, University Col- 

 lege, Dublin, . 167 



[Continued on page 3.] 



The Authors alone are responsible for all opinions expressed in their Communications. 



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