V. CLOCKS AXD SUXDIALS. 419 



without any current. la systems where the electro-motive force is applied 

 directly to move the wheel- work, a single miss of the current destroys the co- 

 incidence of time shown. 



This electro-sympathetic system has for several years been in practical 

 operation in the Royal Observatory and other public buildings in Edinburgh; 

 the Royal Exchange, Manchester ; the General Post Office, Glasgow ; the 

 Royal Dublin Society, Dublin ; Leith Harbour and Docks, and Aberdeen. 

 The clocks at the two ports last named are about two miles distant from the 

 motor clock. The system is likewise about to be introduced into Birmingham. 



1845. Ancient Sundial, for showing the time in any lati- 

 tude, scale for setting the sun's declination, and equation table. 



Elliott Brothers. 



1845a. Ancient Sun Dial with correction for latitude and 

 variation, dated 1579. A. C. Baldwin. 



1848a. Sundial, date 1575. A. C. Baldwin. 



1846. Sissons 9 Universal Ring Dial, for finding the sun's 

 decimation and place in the ecliptic, the latitude of any place, 

 and the hour of the day. Adam Dixon. 



1847. Two Ring-shaped Equatorial Sundials. 



The Breslau Committee. 



1848. Two Sundials, with calendars. 



The Breslau Committee. 



1849. Compass, with Sundial, of the year 1597, with 

 various movable discs for adjusting the zodiacal circle, &c. 



Berggewerkschaftskassc, Bochum, Westphalia. 



1849a. Plaster Cast of a Sundial. The original is made 



of stone and is preserved at the Archaeological Museum at Madrid. 



Archceological Museum, Madrid. 



This was found with a number of other objects at Yecla, in the province of 

 Alicante, Spain. At the upper part there probably was formerly an iron 

 limb to mark the hours, on the Roman system of dividing them in couples. 

 In order to use it the dial was placed in the shade, facing the north. A small 

 spherical concave mirror was placed at a short distance, which reflected the 

 light of the sun upon the dial, and by that means projected the shadow of 

 the needle marking the hours. 



At the base of the instrument are inscriptions in Greek characters, but the 

 language in which they are written appears to belong to one of the Semitic 

 class. A description of this dial was written by Sr. Saavedra, and published 

 in "Discurso leido en la Academia de la Historia de Madrid, porel Sr. 

 Rada." [ ; W jaic ii 



1849a. Poke or Pocket Dial. John Ayting Blagdin. 



This was found about 25 years ago in a stream in Tillington parish, three 

 miles from Petworth, whilst digging for the foundation of a bridge, and may 

 be described as a ring of copper about 1^ inch in diameter, on the outer side 

 of which are engraved letters indicating the names of the months with 



Dd 2 



