February i, 1900] 



NA TURE 



15 



Mr. Lloyd's voyage from England to Zanzibar via the 

 Cape ; of his journey from Zanzibar to Uganda by the 

 German road ; of his residence in Uganda and of his 

 share in the operations against our unfortunate Sou- 

 danese troops, in which he and his colleagues took a 

 prominent part, although, as the author remarks, " the 

 honours and distinctions that were showered upon the 

 military section did not reach the missionaries " ; and 

 finally of his plucky march across the Ituri forests to 

 Ugarrowa (where Stanley first met with his dwarfs in 

 this region), and return home down the Aruwimi and the 

 Congo. 



Mr. Lloyd's hurried march gave him few opportunities 

 of studying the dwarfs, so that he adds little to the de- 

 scriptions of Stanley, Stnhlmann, and Burrows. The 

 only point worthy of notice is that his evidence supports 

 the belief that the pygmies have a fetish worship. It is 

 not clear from Mr. Lloyd's account what clan or tribe of 

 pygmies he met with. How much has been lost by Mr. 

 Lloyd's haste can be gauged from his remarks elsewhere 

 on African customs. He looks on anthropological ques- 

 tions from a typically missionary standpoint. He has a 

 low opinion of the "average African," whose universal 

 laziness he deplores. He describes the aim of the Watoro 

 festivals as "the indulgence in all the evil passions of 

 human nature, fighting and murder, lasciviousness and 

 wanton wickedness. Devil dances of a most disgusting 

 character, witchcraft and fetishism are all practised upon 

 these occasions, and it is at such times that one sees the 

 utter degradation of heathenism." The customs of these 

 Watoro " are most barbarous. For instance, they have 

 an extraordinary practice of breaking off all the front 

 teeth in the lower jaw" ; this is "a thoroughly heathen 

 practice." 



Mr. Lloyd's contributions to the natural history of 

 Central Africa are more startling than numerous. On 

 p. 107 he gives us a photograph of a "boa constrictor" 

 killed on Ukerewe, one of the islands in the Victoria 

 Nyanza. 



The main value of this book is its unwilling witness 

 to the vast improvement effected in the Congo Basin 

 since the establishment of the Congo Free State, 

 twenty years ago. For instance, Mr. Lloyd was able to 

 cross from the eastern frontier to the Atlantic in only a 

 trifle over two months ; he marched safely through the 

 forests with a party of nineteen men ; he found the 

 cannibals of the Bangwa tribe always friendly, and re- 

 marks "that a jollier set of black men I never in all my 

 life had to do with." This testimony as to the revolution 

 of social conditions is the more striking because the 

 author is even more critical of the Congo Free State than 

 he is of the militarism of the Germans and the ritual of 

 the Universities' Mission at Zanzibar. 



TELE P HO TOGRA PH Y. 

 Telephotography. By Thomas R. Dallmeyer. Pp. xv-l- 



148. (London : William Heinemann, 1899.) 

 T N this handsome volume all that is at present known 

 -»- about the theory and practical use of the telephoto- 

 graphic lens is brought together. Mr. Dallmeyer, as our 

 readers may remember, was one of the first who tried to 

 NO. 1579, VOL. 61] 



discover an arrangement of lenses which would produce 

 an enlarged image of any distant object on the ground 

 glass of a camera without any excessive length of camera, 

 and the success which rewarded his labours is now well 

 known. 



It is interesting to remark that the author's attention 

 was first directed to this subject by Dr. P. H. Emerson, 

 who, as we are told in the preface, urged upon him "the 

 necessity of a photographic instrument to enable the 

 naturalist to record incidents that were then only possible 

 by telescopic observation." 



In the year 1892 Mr. Dallmeyer published a small 

 pamphlet containing an interesting collection of papers 

 that had been published relating to his new telescopic 

 photographic lens, and he included in this numerous 

 pictures illustrating the application to the photography of 

 distant objects. This we understand is now out of print. 

 The present volume will therefore be very acceptable 

 to all who use, or intend to use, this form of lens, espe- 

 cially when one is reminded by Mr. Dallmeyer that, 

 with the exception of one or two articles on the practical 

 application of the lens by Mr. Lodge, Mr. Marriage, and 

 Dr. Spitta, the subject has not been handled by any other 

 English writer. 



The author, in his treatment of the subject, introduces 

 the reader first to the elementary properties of light ; he 

 then discusses the formation of images by the pin-hole 

 camera, pointing out some valuable hints relative to the 

 rendering of true perspective effects that may be gained 

 from a study of the images obtained with such an instru- 

 ment. The next two chapters deal with the formation of 

 images by positive and negative lenses, and these serve 

 as an excellent introduction to the following chapters, 

 in which are described the methods of obtaining enlarged 

 images by employing either two positive lens-systems or 

 a combination of a positive and negative system, which 

 constitutes the telephotographic lens. 



From the theoretical the author turns to the practical 

 side of the subject, and in the succeeding chapters he 

 describes the use and effects of the diaphragm, practical 

 applications and working data, concluding with a brief 

 bibliography. 



Quite a distinct feature of the volume is the fine series 

 of illustrations, which brings out vividly, and more than 

 mere words can describe, the great practical use of this 

 form of lens, not only to the stay-at-home photographer, 

 but to those whose duties lie in various directions. 

 Nearly all the plates illustrate views taken, for the sake 

 of comparison, with both the ordinary lens and the tele- 

 scopic lens. Among these we find portraits which illus- 

 trate the value of this lens for obtaining correct per- 

 spective effects in the studio, enlarged pictures of the 

 human eye, eclipse pictures, glaciers photographed at a 

 distance of ten miles, views of an encampment taken 

 from a balloon at a height of 800 metres, a photograph 

 of a grounded man-of-war taken during war time at a 

 distance of two miles, and lastly, reproductions of Mr. 

 Lodge's excellent studies of birds and their nests. The 

 variety of the illustrations gives one an idea of the 

 numerous useful and valuable applications to which such 

 a lens is specially adapted. 



The now great popularity and wide use of the tele- 



