460 



NA TURE 



[March 17, 1887 



and the West Indies. Prof. Suringar, with an assistant, 

 took charge of the botanical work, whilst Prof. Martin 

 was to carry on mineralogical and geological investi- 

 gations, and Mr. Neervoort van de Poll volunteered as 

 zoological collector. The party visited Dutch Guiana, 

 Curacjao, Oruba, 'and Buen Ayre, and made also a short 

 trip to Venezuela.' 



Prof. Martin's preliminary report on Curai^ao and 

 adjacent islands appeared in the Journal of the Dutch 

 Geographical Society (1885) soon after his return to Hol- 

 land ; and the part referring to Guiana was printed in the 

 " ContribvUions towards the Linguistics, Geography, and 

 Ethnography of Dutch India" (1886). Of two short 

 notices on the geology of the countries visited, one was 

 inserted in the Revue Coloniale Internationale ( 1 885), and 

 the other in the Proceedings of the Royal Academy of 

 Sciences, Amsterdam (March 1886). 



The present work is the first part of the author's final 

 report. The narrative of the expedition is cast in the 

 general shape of a diary, but the author usually brings 

 together all the information bearing on the same topic. 

 Strictly scientific matters are excluded, and will be given 

 in a second volume. There is, however, no deficiency of 

 interesting facts referring to the geography and natural 

 history of those out-of-the-way places. The ethnographical 

 chapters on the ancient Indian population of Oruba (with 

 a plate giving samples of old rock-paintings found in cer- 

 tain caves of the island) and on the Bush-Negroes of 

 Surinam are especially valuable. Perhaps Prof Martin 

 might with advantage have given a little more general 

 geological information, which certainly would have been 

 not less acceptable to the readers of this volume than his 

 notes on the botanical and zoological character of the 

 ground covered by his explorations. 



In Guiana the author went up the River Surinam as 

 far as the Negro settlement of Toledo (4° 33' N. lat., and 

 55' 18' W. of Greenwich), a place not formerly visited by 

 any scientific explorer, and indeed not even by any white 

 man. The further ascent of the river would have given 

 no geological results, as the waters began to rise with the 

 beginning of the rainy season, making it impossible to 

 collect specimens from the rocks in the middle of the 

 stream. 



The general situation of Dutch Guiana unfortunately 

 is far from being prosperous. The development of the 

 colony has not kept pace with that of its English neigh- 

 bour. Agriculture, which ought to be its main strength^ 

 is going down-hill, and we believe Prof. Martin is quite 

 right when he expects very little aid from the increasing 

 produce of the gold-washings in the interior. The cause 

 of the evil appears to be rather complicated, as may be 

 seen from a very clever article published by B. E. Colago 

 Belmonte in 7>V«t'//r/ (December 1885 and June 1886). 



The Dutch islands off the northern coast of Venezuela 

 are so very little known outside the narrow circle of 

 people connected with the interests of those colonies that 

 any information about them must be as welcome as if it 

 came from Corea or Madagascar. The islands are very 

 small, measuring only about 1000 square kilometres, and 



' Prof. Suringar, on his way home, spent some days on the Dutch 

 Leeward Islands St. Eustatius and Saba. He has published as yet 

 only a small part of his very interesting report in the Journal of the Dutch 

 Geographical Society (unfortunately in the Dutch language, so that few 

 botanists abroad will be able to read it), besides a paper on a new Melocacti 

 from Curasao, in the Proceedings of the Royal Academy of Sciences, 



are inhabited by 36,000 people, most of them being 

 descendants of Negroes, who speak the Papiamento, a 

 jargon which is a curious mixture of Spanish, English, 

 Dutch, Portuguese, and Carib words. The climate is 

 excessively dry, and the vegetation is therefore very poor. 

 For the same reason Curasao is an important sanitary 

 station ; and as the port of Willemstad is one of the safest 

 in existence, it is to be expected that the island will gain 

 in importance by the opening of the canal through the 

 Isthmus of Panama. The principal article of export is 

 phosphate of lime, which is found there in large quantities 

 and of considerable richness. Here as well as on the 

 Venezuelan islands of Los Roques, Orchila, Las Aves, 

 Los Testigos, &c., the phosphates owe their origin to an 

 epigenetic change of the coralline limestone, which be- 

 came infiltrated with phosphate of lime from overlying 

 deposits of guano, exposed to the action of the periodical 

 rains. All these islands have a nucleus of eruptive rocks 

 (diorite, diabase, gabbro, eclogite) : the same geological 

 constitution exists in the central hill of the peninsula of 

 Paraguand and in the mountain-ridges of La Guajara. 

 We have thus a line of volcanic out-flows corresponding 

 to a long fissure running from east to west. 



The chapter referring to Prof. Martin's visit to Vene- 

 zuela is short, as was his stay in that country. It does not 

 pretend to give anything new, but it is a very proper con- 

 clusion to the author's " Recollections of Travel." 



When speaking of the so-called flight of flying- 

 fishes. Prof Martin says it appeared to him that the 

 animals now and then, by a jerk of their tails, gave 

 a new impulse to their ascending movement, in addi- 

 tion to the work done by their fins (" als ob die Thiere 

 sich mit Hiilfe des Schwanzes manchmal von neuem 

 emporschnellten und so die Arbeit der Flossen unter- 

 stutzten "). Our own observations of several species of 

 flying-fishes lead us to adopt entirely Prof K. Mobius's 

 conclusions, viz. that the pectoral fins do no propelling 

 work at all, but only keep the body of the animal resting 

 on the air, and that the occasional rise in the line of 

 movement, when the latter goes against the wind and the 

 direction of the waves, is due to the lifting pressure of the 

 wind, which ascends the opposite slope of the wave (K. 

 Mobius, "Die Bewegungen der fliegenden Fische durch 

 die Luft," Leipzig, 1878). 



Prof Martin's style is very clear and fresh. The plates 

 which accompany the book, mostly engra\'ed from his own 

 drawings, are excellent illustrations of scenery and ethno- 

 graphical objects, and the whole volume is got up in a 

 manner which is highly creditable to the publisher. We 

 expect with great interest the concluding part of this 

 valuable report, which, no doubt, will be an important 

 contribution to South American natural history. ■ 



A. Ernst 



HYDRAULIC POWER AND HYDRAULIC 

 MACHINERY 

 Hydraulic Power and Hydraulic Machinery. By H. 

 Robinson, M.I.C.E., &c. Pp. xiv. -f 190, and 42 plates. 

 (London: Charles Griffon, 1887.) 



THIS work purports to "record existing experience in 

 this branch of engineering." It is divided into 

 thirty-five short chapters (not numbered, and therefore 



