8 
LEWIS EVANS-—ADDRESS ! 
Secondly, this instrument exhibits a knowledge of astronomy much 
in advance of anything traceable in all the other Greek and Roman 
dials which have been found. Thirdly, this is the only one of 
the four Roman portable dials which remains absolutely perfect and 
uninjured. And fourthly, it shows the equinoctial hours such as 
those by which we now reckon. It was found in Austria, and was 
probably made about a.d. 250-300. On its hack are engraved the 
Fig. 9.—English Compass Dial. 
names and latitudes of many Roman provinces, and it can he used 
in any latitude. Its method is essentially the same as that of 
the universal ring-dial, of which I exhibit several specimens this 
evening: an English one (Fig. 8, p. 7) made by Elias Allen of 
London, about 1630, one made by J. A. Pfeiffer at Coburg about 
1720, and another German one mounted on a stand beside a 
large English dial about 1730. This is one of the best and most 
Fig. 10.— German Crucifix Dial. 
convenient forms of pocket-dials: the time is shown by a ray 
of light falling on the centre line of the hour-ring. In use the 
hour circle is turned on its pivots until it stands square to the 
meridian ring, the slider in the middle bar is set to the name of 
the month, and the suspension-ring being set to the latitude of 
the place, the dial is held by the ring and turned so that a spot 
of sunlight shining through the slider falls on the centre line 
