i a Mijcellanea Curio fa. 



fhall nearly reprefent the Figure cf the Sea, and 

 C/, CD, CF, CJ, fhall be the heighths of the 

 Sea in the places /, D, F, </, in all which it is 

 High-water : And feeing that in tv/elve Hours 

 time, by the diurnal Rotation of the Earth, the 

 Point F is transferred to/, and d to D : The 

 heip-bc of the Sea C F will be that of the High- 

 water when the Moon is prefent, and C / that 

 of the other High-water, when the Moon is un- 

 der the Earth : Which in the cafe of this Fi- 

 gure is lefs than the former CF. And in the 

 oppofite Parallel D d, the contrary happens. The 

 Rifing of the Water being always alternately 

 greater and lefs in each place, when , it is pro- 

 duced by the Moon declining fenfibly from the 

 Equinoctial ; that being the greateft of the two 

 High-waters in each diurnal Revolution of the 

 Moon, wherein fhe approaches neareft either to 

 the Zenith or Nadir of the place : W' hence it is, 

 that the Moon in the Northern Signs, in this 

 part of the World, makes the greateft Tides 

 when above the Earth, and in Southern Signs, 

 when under the Earth ; the Effect being always 

 the greateft where the Moon is fartheft from the 

 Horizon, either above or below it. And this al- 

 ternate Increale and Decreafe of the Tides has 

 been obferv'd to hold true on the Coaft of £«» 

 gland, at Briftol by Captain Sturmy, and at Ply- 

 mouth by Mr. Coleprejfe. 



But the Motions hitherto mentioned are fome- 

 what alrer'd by the Libration of the Water, 

 whereby, though the Aclion of the Luminaries 

 fhould ceafe, the Flux and Reflux of the Sea 

 would for fbme time continue : This Conferva- 

 tion of the imprefs'd Motion diminishes the dif- 

 ferences that otherwife would be between two 

 conftquent Tides, and is the reafon why the 



higheft 



