OF THE OBSERVATORY OF CAMBRIDGE BY GALVANIC SIGNALS. 



495 



Fourth Set. — Cambridge Signals — (continued.) 



Notes to the foregoing Observations. 



%• The letters D, T, and B are put respectively for Mr Dunkin, Mr Todd, and 

 Mr Breen. The Batches and Nos. of the series to which the notes apply have asterisks 

 attached to them. 



No. 5, 58,0 in T's observation is probably a mistake for 59,0. 



Batch IV., Note by B, 'bad, — too quick.' 



No. 30, B's observation appears to be I s in excess. 



No. 38, T's observation is 10 s in excess, as shewn by B's. 



Batches X. and XII., * Noise.' (T). 



Batch XII., ' At the end of this batch I found myself counting the clock a second in 

 error.' (D). 



No. 88, B's observation was marked ' bad.' 



No. 91, B's observation is probably 1* in defect. 



Batch XVIII., 'good' (T) ; 'very good' (B). 



Nos. Ill and 113, by comparison of T's times with B's it appears probable that 30,8 is a 

 mistake for 29,8, and 55,6 for 56,6. 



No. 133, T's signal-time was doubtful. 



Batch XXVII., ' bad,— confused.' (T). 



The noted times in batches V., XV., XVII., and XIX., are respectively the times of 

 transit of B .A. C. 4941, 7 Serpentis, 10 Serpentis, and 11 Serpentis, across the wires of the 

 Greenwich Transit Circle. 



The omissions in Nos. 1, 6, 19, 35, 43, 82, 110 and 114 appear in most cases to be due to 

 the observers being unprepared, which might arise either from a miscounting of the warning 

 signals, or from the small intervals allowed between the batches. In the observations of 

 May 18, the batches were separated by larger intervals, and in consequence a smaller number 

 of signals were given in the course of the hour. 



Vol. IX. Part IV. 



64 



