VOL. 



LV.] 



PHILOSOPHICAL TRAKSACTIONS. 



271 



8 leagues in circumference. The whole squadron passed between this island and 

 Dominica, and anchored in a very good haven, to the w. of St. Christine, in 

 the latitude of 9° 30'; near which they found a rivulet of very fine and fresh 

 water. The coasts of all the islands seemed in general very safe and commodious 

 for shipping. In this harbour they found all kinds of refreshment: as fowls, 

 hogs, sugar-<;anes, plantanes, cocoa nuts, and many sorts of other fruits. They 

 conversed with the natives of the country, and erected 3 crosses." 



Besides the countries already mentioned, it should seem, from Mr. de Lisle's 

 map of the southern hemisphere, that there are many islands situated between 

 the parallels of 5° and 23° of s. latitude, in the great Pacific Ocean; the most 

 remarkable of which, together with those already mentioned, are given in the 

 following table. 



w. Ion. s, lat 

 Island of St. Peter, according to some maps 130. . 18 



Islands of Mendoza 135. . 9J 



Islands discovered by Quiros, )605 138. . 21 



Isles des Tiburons, or Dog island 141 . . 16 



Isle Habitee 144. . 17 



Islands of St. Barnard 150. . U 



Water island 151.. 15 



Fly island 153. . 15j 



Land discovered by Mendana 157. . 4 



w.lon. s.lat. 



Isle de la Belle Nation l6o. . 12 



Island of Jesus 162. . 7 



Rotterdam isle 173. . 20j 



Amsterdam isle 174. . 21 



Solomon isles 175. . 10 



Island of Taumaco . . .j.^ , <i ^ . 177. . 13 

 Prince William islands ...... 178. . 17 



Terra Aastralis 190. . 15 



It appears then not only possible, but highly probable, that observers may be 



stationed in the South seas. Mr. H. therefore computed the parallactic angle for 



different longitudes and latitudes, answering to such places whose positions seem 



to be most certainly known ; the result of which calculations is given at one view 



in the following table. 



Places names ^"'*' '"'^''"3' Second internal Tot. eff. of Diff. in tot. 



contact. contact. par. = 8".7. dur.fr. Tor. 



21 0. . Island of St. Peter 6"" 10' 6" 6" 12"" 16' 23"" 06' 



9 30. . Mendoza isles 4 31 6 49 II 20 23 



20 30. . Amsterdam and Rotterdam isle 6 19 4 42 11 1 22 41 



15 0. . Terra Australis 5 43 3 I6 8 59 20 39 



w. Ion. s. lat. 



155 42. 

 135 0. 

 173 0. 

 190 0. 



By the last column it appears, that if an observer be stationed in any of the 

 above places, perhaps in any part of the South seas where the whole transit is 

 visible, and the total duration observed there be compared withe nat at Tomea", 

 we may obtain a difference in time from 20 to 24 minutes ; which is indeed so 

 considerable, that the sun's true distance must be ascertained more exactly than 

 can possibly be expected from any other method. 



But, if it should be found impracticable to station an observer in the South 

 seas, the loss may in a great measure be repaired, if the transit be observed in 

 such parts of North America where the whole is visible. At Mexico the total 

 ingress will happen when the sun is very near the meridian ; and if the longitude 

 of the place and the general computation may be depended on, the beginning of 



