46 Scientific Proceedings, Royal Dublin Society. 



sions than it really is. The occultations at the dark limb are, on 

 the contrary, so sudden as almost to take the observer's breath 

 away, if he is not accustomed to such work. 



During a total eclipse the effect of irradiation is almost wholly 

 absent, and the moon's light is so much reduced, that very faint 

 stars can be observed as they disappear, or emerge from, behind the 

 body of the moon. 



Yery extensive preparations were made for the eclipses which 

 took place on October 4, 1884, and on January 28th of this 

 year. In view of the latter, Dr. Dollen prepared a list of 300 

 stars which would be occulted during the eclipse, and computed 

 the times for 120 observatories. A large number prepared to 

 co-operate in the work; but as far as the accounts received up to 

 the present go, it would seem that the weather, at a great many of 

 them, was very unfavourable. At Greenwich, nine telescopes were 

 provided with observers ; but clouds interfered greatly with the 

 observations. Only four of the larger instruments were able to 

 see the faint stars occulted, and altogether they obtained only seven 

 observations of disappearance and fifteen of reappearance. 



At Poulkova, where three instruments were employed, the 

 atmosphere was clear, and fifty occultations were observed. 



At Leipzig, Dresden, Yienna, and Kasan, it was quite cloudy ; 

 at Berlin, Paris, and Grotha, partially so, and only a few observa- 

 tions were made. At Bothkamp thirty occultations were observed 

 in a clear sky, and at Moscow the night was fine ; but the num- 

 ber of occultations is not recorded. 



At Dunsink we were exceptionally favoured. In the early 

 part of the week the weather had been very bad; but it cleared up, 

 as if for the occasion, giving us a splendid night for observing on 

 the 28th. 



I was observing with the "South" Equatorial of llf inches 

 aperture, which was connected with the chronograph described in 

 the Sixth Part of the " Dunsink Observations," which has just 

 been published, and in which a copy of one of our chronograph 

 sheets is given. 



The occultations allotted to Dunsink — 73 in number — followed 

 each other so rapidly that it would have been impossible to set the 

 micrometer for each star to the required position angle. Accord- 

 ingly, I set the single wire in the parallel, and had on the chair 



