Feb. 4, 1 875 J 



NA TURE 



265 



man in South America to a time which must be mea- 

 sured by thousands of years. 



It seems to us a herculean task to attempt to unravel the 

 ethnology of Peru, which we suspect can only be adequately 

 done in connection with that of the whole American con- 

 tinent ; but it is a task which is well worth attempting. A 

 vast amount has been written on the subject, and there 

 exists a great wealth of material ; it seems to us that 



Fig. 4. — Ruins of Reputed Temple of the Sunatlacha eam-iL — Hutehiiuun 



what is now wanted is a man possessed of the necessary 

 wide grasp of mind and extensive knowledge to set him- 

 self to collect, arrange, and sift this material and investi- 

 gate on strict scientific principles the bearing of the 

 results. From such a process, we believe, some definite 



KiG. 5 —Part of Ruins of Double Wall of Temple of Rimac— Hutchinson. 



and valuable conclusions would be arrived at, as definite, 

 perhaps, though not nearly so comprehensive, as those 

 which have been reached concerning the Indo-European 

 peoples ; for there still remains much material to bring 

 together, and no time should be lost in setting about the 

 work. Mr. Hutchinson suggests that if some one would 

 do for the remains in Peru what Schliemann has done for 

 those of Troy, and George Smith has done for those in 



Assyria, the results would be of higher value than any 

 yet achieved. Let some one with the patience, enthusiasm, 

 and knowledge of Dr. Schliemann, devote the necessary 

 time to the careful excavation and study of the mounds 

 and clay-covered buildings, and we are sure the results 

 will well repay the labour. Let us hope that the present 

 Peruvian Government will be patriotic and generous 

 enough to inaugurate and bear the expense of the work, 

 and thus gain for themselves the admiration and 

 thanks of the civilised world. Talking of Dr. Schlie- 

 m^inn, Mr. Hutchinson points out some very remarkable 

 coincidences between the buildings and relics which that 

 explorer has unearthed, and those which Mr. Hutchinson 

 himself has found in Peru. Whether this be more 

 than a coincidence it would be rash at present to con- 

 jecture. 



Mr. Hutchinson's work must be regarded as one of 

 the most important contributions that have been made 

 to the archeology of Peru, and we hope that though no 

 longer resident in the country, he will continue to investi- 

 gate the subject and help to reduce its present confusion 

 to something like order. We think, however, he might 

 have a little more patience with the theories of other inves- 

 tigators, and not hastily cast them aside as unworthy of 

 notice; the labours of all competent and earnest workers 

 bhould be seriously studied, for thus only can the full 

 tuilh be arrived at ; even in the legends of Garcilasso he 

 might find some speck of valuable truth. 



WATSON'S "DESCRIPTIVE GEOMETRY" 

 A Course in Descriptive Geometry. By William Watson, 

 Ph.D. 4to. double columns, pp. xi., 147, with thirty- 

 two plates and three double plates of stereoscopic 

 views. (Boston : Osgood and Co. London ; Longmans, 

 Green, and Co., 1874.) 



DESCRIPTIVE Geometry affords the practical 

 means of dealing with geometry in three dimen- 

 sions, in the same manner that Practical Geometry, that 

 is to say, the intelligent use of drawing and of graphical 

 methods, deals with plane geometry. If, in solid 

 geometiy, we concerned ourselves only with points and 

 with lines, whether straight or curved, we might say that 

 descriptive geometry was simply the science of plan and 

 elevation. As regards the point and the line, it is 

 nothing more. But what distinguishes descriptive 

 geometry, as it was published to the world in Monge's 

 celebrated treatise, from what was already known to 

 every intelligent builder or carpenter, is the means of 

 indicating surfaces, whether plane or curved, as well 

 as of representing points or lines. We use the terms 

 indicating and representing advisedly, as carrying with 

 them a real distinction, which, we regret to see, is not 

 always brought prominently forward in the treatises, and 

 sometimes fails to be perceived by the student until he 

 has wasted valuable time in groping after a misappre- 

 hension. It is indeed evident that a surface cannot be 

 represented in the same sense that a point and line are, 

 for its plan and elevation would be simply two black 

 patches, the contours of which would give the boun- 

 daries of the surface in certain directions, but would fail 

 to represent the surface itself. Now, the method pub- 

 lished by Monge regarded a surface, whether plane or 

 curved, as completely indicated so soon as its geo- 



