260 CONTENTS. 



Pago 

 OliSEKVATlONS OF THE EGRESS OF VENUS, 1874, DECEMBER 8 : 



Report of Captain C. Orde Browne 289 



Comparisons of the Clocks employed 294 



Observations by Mr. F. M. Newton 295 



, , Miss E. M. Newton 296 



Discussion of the Micrometric Observations 297 



Final Equations resulting from the Observations of Egress at Mokattam 299 



Semidiameter of Venus. 302 



Time of Internal Contact inferred from the Micrometric Measures of Cusps .... 302 



MERIDIONAL AND ALTAZIMUTH OBSERVATIONS IN TABULAR ARRANGEMENT : 



Table XIII. Level Error of the Transit Instrument 304 



Table XIV. Collimation of the Transit Instrument 306 



Table XV. Azimuth Error of the Transit Instrument 307 



Table XVI. Meridional Transits 307 



Table XVII. Errors and Rates of the Transit Clock 314 



Table XVIII. Errors and Rates of the Altazimuth Clock. 315 



Table XIX. Zenith Distances and Inferred Co-latitude 316 



Plate VIII. Plan of the Environs of Cairo to face 261 



Plate IX. Plan of the Encampment on Mokattam Hills 262 



Plate X. Diagrams relating to the Egress of Venus as observed at Mokattam . 296 



