COUNTING THE SUNNY HOURS 



G. B. ARTHUR 



The Sun-dial of Olden Days Still Serving in Twentieth-Century 

 Gardens — How to Lay Out the Dial According to Latitude 



|N "YE goode olde days" back in 1600 every garden had 

 its sun-dial. But right soon thereafter a Hollander 

 made a thing with weights and cogs which he called a 

 clock, and which, though passing strange, would tell 

 the time without the sun. And then, forsooth, such was the 

 fickleness of the people that every household needs must have a 

 clock; wherefore sun-dials went out of style notwithstanding 

 their faithful service since well before n 00 b. c. 



The "dial of Ahaz" of Second Kings, XX, 11, and Isaiah 

 XXXVIII, 8, probably belonged to the eighth century b. c. 

 Two centuries later the Babylonians passed the sun-dial on to 

 the Greeks while the Romans captured their first one from the 

 Samnites in 290 b. c. 

 They brought another 

 from Sicily in 263 b. c, 

 but this one, made for a 

 southerly latitude, was 

 not accurate for Rome, 

 though they did not dis- 

 cover that for well nigh a 

 hundred years. Vitruvius, 

 the celebrated Roman en- 

 gineer, wrote in the first 

 century B. C. of thirteen 

 forms in use in his day. 

 Charles II of England set 

 up in the royal garden at 

 Whitehall a monumental 

 piece in which there were 

 nearly three hundred sun- 

 dials, of seventy-five var- 

 ieties. As recently as 1907 

 the Right Honorable Sir 

 William Mather, of Man- 

 chester, England, pre- 

 sented to Princeton Uni- 

 versity an exact copy of 

 the famous Turnbull sun- 

 dial at Corpus Christi 

 College, Oxford. 



Sun-dials will never 

 really go out of fashion. 



They have too many rich associations; historic, artistic, and sen- 

 timental. A sun-dial is an essential part of every garden. It 

 adds a graceful touch of old-world history, a flavor of antiquity. 

 It is a monument of far more grace and utility for public places 

 than many of our portrait statues, and it has a literature all its 

 own. 



Somehow with all our clocks and jewelled watches we have the 

 notion that sun-dials are merely ornaments — crude time-keeping 

 devices that sufficed for the dark ages, or relics of barbarism 

 perhaps. But that is far wrong. The sun-dial requires neither 

 winding nor setting; it never balks at inattention; it has no 

 lapses of dependability. 



It is always right. That is, it is always in agreement with the 

 true time by the sun. It disagrees with "standard" time, of 

 course, because that is a paltry artificial thing, a mere approxi- 

 mation. For that matter sun-dial time can be reduced to stan- 

 dard time with the aid of a table of equivalents. Still, anybody 

 can have standard time, and it is something to have the true 

 time by the sun on the meridian of one's own garden. 



Far from being a common thing to be purchased carelessly, 



Lahlude 



out uia 

 Dial ftr 

 Laliiu.de 40° 



A SUNDIAL MUST BE SET FOR ITS LATITUDE 



Latitude 40 , for which this diagram is worked, covers a line drawn through 



Philadelphia, Columbus, the Nebraska-Kansas state line; is a little north of 



Dayton, Springfield, St. Joseph, Denver, Reno; and reaches the coast on the 



north line of Mendocino County, California 



How to adjust the dial for any given longitude is explained in the article 



the sun-dial possesses an individuality which is at once peculiar 

 and distinctive, for it must be made for one location, and it will 

 fit that one alone. The governing requirement is the latitude. 

 An accurate sun-dial can be purchased, provided it is purchased 

 for a specified latitude; but lacking that all-important coinci- 

 dence with its position on the globe, it is worthless. 



FORTUNATELY gnomonics, which is the art of con- 

 structing sun-dials, flourishes to-day just as it has flourished 

 in any other age, for sun-dials have been made in so many forms, 

 and in so many combinations of beauty and utility, that they 

 are ever in demand. For the benefit of the gardener who wishes 



to time his dial accurately 

 the method of laying one 

 out is here given. 



In Figure 1 there is a 

 portion of a dial — which 

 is the horizontal plate with 

 the numerals around the 

 base line. In the be- 

 ginning, while the dial may 

 seem to be a semicircle, it 

 is really two quadrants 

 separated on the line 

 A-XII by the thickness of 

 the style (the upstanding 

 piece which casts the 

 shadow.) The sun-dial 

 will not be accurate if this 

 thickness is ignored. 



For the left hand quad- 

 rant begin at A, and 

 draw a line A-B at an 

 angle with A-XII corre- 

 sponding to the degree of 

 latitude. At any conven- 

 ient point erect a line B-C 

 perpendicular to A-XII. 

 From B draw a line B-D 

 at right angles to the line 

 A-B. The angle DBC 

 will be the same as BAC, 

 or the same as the degree of latitude. 



Now set the compasses for the radius D-B, and describe the 

 quadrant D-F touching the end of the line D-B. Draw the 

 line D-G perpendicular to the centre line A-XII. 



Divide the quadrant D-F into six equal parts, and draw 

 radial lines from the centre of the quadrant E to cut the line 

 D-G; marking these intersections 1, 2, 3, 4, etc. Draw other 

 radial lines from the centre A through these intersections to 

 the base line of the sun-dial, locating the hour divisions I, II, III, 



mi, v. 



Between 2 and 3 the half-hourly and quarter-hourly divisions 

 are laid out by the same method. 



The style can have many variations of form so long as the top 

 angle (shown in Figure 2) is the same as the degree of latitude, 

 agreeing with the angle BAC used in laying out the dial. The 

 sloping side must be straight and true, but the other two sides 

 may be made to suit any design. The length L is the distance 

 from A to the inner circle of the dial at XII, and the style is 

 mounted with the high end at twelve. 



Though the most common form to-day is semicircular, many 



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