I02 BROWX : 



south. If the sun be unobscured a report follows and those 

 that hear it look at their much trusted watches ; almost 

 always, however, with disappointment at not finding- them 

 mark twelve o'clock. 



And, generally, if we compare the hour and minute of the 

 day as declared by a good and trusty timekeeper with that 

 marked l)y a well and carefully adjusted dial we shall see a 

 difference which is sometimes greater and sometimes less and 

 which at four periods of the year disappears entirely. 



The dial marks " apparent time " and records, in daylight 

 and clear weather, the true position of the real sun. 



The clock marks "mean solar time" and is a conven- 

 tional record of the motions of an imaginary sun. 



I shall set forth if I can the difference between the two 

 records and the uses of each. 



The sundial is in these days rather for ornament than for 

 use. It is of varied forms; vertical, horizontal or inclined; 

 on wall and column and big block of masonry. Fancy 

 wearies herself in its decoration ; whole books, and very pretty 

 entertaining books too, have been written about the sentiment 

 of this implement, and the stern and melancholy rhymes 

 which motto it. 



There is a vertical dial on the wall of the house at Bar- 

 tram's Garden. 



Inside the Gas Works domain at Market and T.wenty- 

 second or thereabouts there stands a dial on a brick pillar. It 

 dates from the time of open field in that neighborhood ; and 

 the subway works seem to have spared it. 



The most usual form of dial is a level face figured five 

 hours on each side of noon. The st\de that casts the shadow 

 is accurate!}^ adjusted on the north and south line, and raised 

 at an angle equal to the latitude of the place so as to point as 

 nearly as may be to the pole of the heavens. For those who 

 know other things instead of this — the elevation of the pole 

 is equal to the latitude of the observer. The shadow falls on 

 the noon mark when the sun passes the meridian and the 



