142 PROF. W. J. DAKIN : EXPEDITION TO THE 



Further information is, however, to be obtained from the engine-room 

 observations already referred to. If isotherms are plotted from the readings 

 of June 1911, it will be seen that a definite tongue of warmer water extends 

 down the coast of West Australia, the tip reaching to about the Abrolhos 

 Islands (text-fig. 3). During this time, a southern movement of equatorial 

 water was taking place, and it was separated from the coast by a distinct 

 zone of cold water which was still more obvious during the following month 

 and extended from the Leeuwin northwards. 



The evidence so far collected goes to show, then, that there is a general 

 tendency for the temperature of the sea at the Abrolhos to be slightly higher 

 than that at the coast, or at all events for certain periods, and that an equatorial 

 current may account for the phenomenon. The difference between the 

 Abrolhos Islands and the mainland may not however lie in the same direction 

 at all seasons of the year. It is to my mind noteworthy that it is during the 

 winter that we are sure of a certain higher degree at the Abrolhos than at 

 Geraldton, and it is not the actual amount of difference that I regard as 

 important but the fact that the temperature at the Abrolhos Islands is pulled 

 up during the winter months, when it probably rarely falls below 20° 0. 

 Indications of a tropical current reaching the Abrolhos in the manner 

 described, do not appear on the American Pilot Charts of the Indian Ocean, 

 but the following quotation from Otto Kriimmel's 'Oceanographie,' 2te. 

 Aufl. ii. 675-6 (1911), shows that other investigators have noticed these West 

 Australian conditions. 



" I in Vergleich zur homologen Benguelastromung ist die westaustralische 

 nicht durch die gleichen niedrigen Temperatnren an ihrem Kiistenrande 

 ausgezeichnet, wie wir sie ohen darlegen konnten. Wir haben als Ursache 

 dieses Verhaltens die abweichende Kon figuration des australischen Festlands 

 zu bezeichnen, welcbe einem von Norden und Nordosten her kommenden 

 warmen Strom entlang der Kiiste einen Weg nach Siiden unci somit in den 

 Riicken des Siidostpassats gestattet. Dadurch ist also eine ausreichende 

 Kompensation an der Oberflache von Norden wie von Siiden her ermoglicht; 

 man kann schon aus dem Auftreten von Riffkorallen dei den Houttmanischen 

 (28J-° S.B.) auf dauernd warmes Wasser schliessen. Ein warmer Strom 

 kommt insbesondere im Sudsommer aus der Timorsee und, in den Buchten 

 Nordwestaustraliens Neerstrome entwickelnd, geht er nach Siidwesten, um 

 anscheinend bei der Dirk-Hartoginsel, dem westlichsten Punkte des 

 Festlandes, nach Siiden umzubiegen und nach dem Befund der Gazelle- 

 Expedition 16 Seemeilen in 24 Stunden nach Stidosten zu laufen." 



We have seen that Saville Kent emphasized the fact that the marine fauna 

 of the Abrolhos differed in an extraordinary manner from that of the 

 adjacent coasts, and he accounted for this bj r the assumption of a current, 

 the existence of which is now supported by a considerable amount of evidence. 

 The Hamburg Expedition of Michaelsen and Hartmeyer did not visit the 



