HELIOTROPES. 227 



matrons upbraided they execrated they insulted they 

 triumphed. In a word, they never desisted from buffeting 

 their adversary till they had torn him in a hundred pieces. 



LETTER LXXXVI. 

 TO THE HON. DAINES HARRINGTON. 



SELBORNE. 



monstrent 



Quid tantum Oceano properent se tingere soles 

 Hyberni ; vel quse tardis mora noctibus obstet. 



GENTLEMEN who have outlets might contrive to make 

 ornament subservient to utility; a pleasing- eye-trap might 

 also contribute to promote science : an obelisk in a garden or 

 park might be both an embellishment and a heliotrope. 



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 

 expense ; 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 helio- 

 trope to the north of it.* 



* Mr Mark Watt lias invented a very curious and interesting instru- 

 ment, which he calls the heliastron, or solar compass. Having observed 

 the daily variation of barometers and the magnetic needle, and remarking 

 that a similar series of alternate changes were more or less observable in 

 every instrument capable of indicating a slight alteration of the impression* 

 made on them, and that these diurnal changes bore a proportionate 



