E-ambaut — Japanese Clocks. 341 



equations of the same form as equation (2), from which I obtain 

 <p = 33° 46' and x = 12° 18'. The two dates to which the scales 

 correspond are, however, so close together (being separated by only 

 15 days) that these values are liable to considerable error. 



The third and smallest of the three clocks is in one respect, 

 perhaps, the most interesting. It has a single pointer attached to 

 the weight, as in the case of the second clock, but differs from the 

 others in being controlled by a balance spring instead of a pendu- 

 lum. There are traces of a set of movable indices, as in the case 

 of the second clock, but these have been removed, and a slip of 

 metal cemented along the slot in which they used to slide, and on 

 this slip are marked spaces of equal length. We have, therefore, 

 in the case of this clock, which has been remodelled by the previous 

 owner in accordance with western ideas, actual evidence of the 

 great Europeanizing influence which is at present so active in 

 Japan. 



NOTE ADDED IN PEESS. 



Since this Paper was read I have been enabled, by the kind- 

 ness of Mr. H. A. Cosgrave, to examine another Japanese clock 

 belonging to a friend of his, which is constructed on the same 

 principle as those described above. It has a reversible dial, similar 

 to that of the second clock described. From the two scales on 

 this dial I find <j> = 30° 7', and x = 13° 1'. This value of <j> would 

 bring us down as low as the island Yakemosima, at the south 

 point of Japan; but the value of x agrees very well with that 

 found on page 339. I am also indebted to Prof. Alexander, of 

 Trinity College, Dublin, for a description of a curious clock which 

 he came across in Japan, and which was controlled by two balance 

 wheels oscillating in different periods, one for the day and the other 

 for the night. There was an arrangement in the clock by which, 

 when the wheel that was working during the daylight hours had 

 performed the proper number of oscillations, it was automatically 

 thrown out of gear, and the other came into play to " rule the 

 night." The two wheels were regulated by a movable pointer 

 like the regulator of a watch, but the time of oscillation of one was 



