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AMERICAN HOMES AND GARDENS 



August, 1908 



up and down an apparatus in the form of steps. Such 

 chambers, he remarks, were in use in Eastern observatories 

 till the middle of the eighteenth century. The celebrated 



A Pocket Sun-dial with Compass Arranged for Twenty-four 

 Important Cities 



dial of Ahaz, which was probably set up about 800 years 

 before Christ, was in all likelihood nothing more than a cir- 

 cular staircase leading up to a column or obelisk, the shadow 

 of which, falling on a greater or smaller number of steps, 

 according as the sun was low or high, indicated the position 

 of the sun, and thus told the time of day. According to the 

 Bible story, the shadow was miraculously made to recede 

 ten steps, as a sign that Isaiah's prayer in behalf of Hezekiah 

 for an extension of his life had been favorably answered. 



The almost universal use of sun-dials in ancient times is 

 well assured. In the history of ancient Greece, frequent 

 references occur to a shadow by means of which the time of 

 day was determined, but it is not known what means was 

 employed for casting the shadow. One theory advanced was 

 that the gnomon was each man's figure, the shadow of which 

 he measured, probably by pacing off the distance it covered. 

 But whatever the method was, it was imperfect and the dial 

 required frequent alterations during the year. Far less de- 

 terminable, however, is the secret of the method employed by 



of the wonders of that imperial city. On the triumphant 

 return of Augustus from Egypt be brought with him a tower- 

 ing obelisk, which he set up as the gnomon of a huge sun- 

 dial among the stately arches and porticos where the Roman 

 citizenswerewont to assemble at the public games. The hours 

 were marked out by a circle of gigantic figures, so arranged 

 that they might catch the earliest and latest rays of sunlight 



Brass Pocket Sun-dial Elaborately Engraved with 

 Astronomical Signs and Tables 



and thus mark the dawn and close of each day. Not a trace 

 of this obelisk is left. How long it remained in position is 

 not known, but, like many others of note, it disappeared, and 



Brass Dial for Telling Time and Observing the Planets 



A North Shore Sun-dial 



the first inhabitants of Arabia, who without the use of any 

 instrument could determine the time of year or of day with 

 accuracy. At a later date, when Rome was at the height of 

 her glory, the great sun-dial in the Campus Martius was one 



the practise of setting up sun-dials gradually fell into disuse. 

 The usual form of the Greek and Roman dials was the 

 "hemicyclium," which is described as "an excavation nearly 

 spherical in a square block of stone, within which the hour 



