226 NATURAL HISTORY 



Any person that is curious, and enjoys the advantage of a 

 good horizon, might, with little trouble, make two heliotropes ; 

 the one for the winter, the other for the summer solstice : and 

 these two erections might be constructed with very little ex- 

 pense ; for two pieces of timber frame-work, about ten or 

 twelve feet high, and four feet broad at the base, and close 

 lined with plank, would answer the purpose. 



The erection for the former should, if possible, be placed 

 within sight of some window in the common sitting parlour ; 

 because men, at that dead season of the year, are usually 

 within doors at the close of the day ; while that for the latter 

 might be fixed for any given spot in the garden or outlet : 

 whence the owner might contemplate, in a fine summer's 

 evening, the utmost extent that the sun makes to the north- 

 ward at the season of the longest days. Now nothing would 

 be necessary but to place these two objects with so much 

 exactness, that the westerly limb of the sun, at setting, might 

 but just clear the winter heliotrope to the west of it on the 

 shortest day ; and that the whole disc of the sun, at the longest 

 day, might exactly at setting also clear the summer heliotrope 

 to the north of it. 



By this simple expedient it would soon appear that there is 

 no such thing, strictly speaking, as a solstice ; for, from the 

 shortest day, the owner would, every clear evening, see the 

 disc advancing, at it's setting, to the westward of the object ; 

 and, from the longest day, observe the sun retiring backwards 

 every evening at it's setting, towards the object westward, till, 

 in a few nights, it would set quite behind it, and so by degrees 

 to the west of it : for when the sun comes near the summer 

 solstice, the whole disc of it would at first set behind the 

 object ; after a time the northern limb would first appear, and 

 so every night gradually more, till at length the whole diame- 

 ter would set northward of it for about three nights ; but on 

 the middle night of the three, sensibly more remote than the 

 former or following. When beginning it's recess from the 

 summer tropic, it would continue more and more to be hidden 

 every night, till at length it would descend quite behind the 

 object again ; and so nightly more and more to the westward. 



