Notices respecting New Books. 59 



manner, and that indeed entire treatises might be written upon the 



subject of some chapters There are phenomena which appear 



to require for their production causes hitherto unexplained, which 

 must be looked for possibly outside the globe itself. Such are cli- 

 matal changes. Such is also the remarkable fact that the grand 

 efforts of elevatory action appear to have been paroxysmal, and 

 after slumbering for long ages to have been more intense at cer- 

 tain periods, the last of which was subsequent to the Eocene. 

 These questions are left for a rising generation of physicists and 

 astronomers, who, it is hoped, may think the ascertained facts _ of 

 Geology a worthy field for the application of exact scientific 

 methods." 



There is a good summary of the contents of the several chapters, 

 and an Appendix, which takes notice of two memoirs (unpublished 

 at the date of publication of the ' Physics ')— one by Mr. G. H. 

 Darwin, " On the Stresses caused in the Interior of the Earth by 

 the Weight of Continents and Mountains," and the other by M. 

 Ed. Eoche. An Index closes the volume. 



The Solution of the Pyramid Problem. By Eobert Ballakd. New 



York : John Wiley and Sons. 1882. (109 pp., 75 woodcuts.) 

 This is another addition to the " curious " literature about the 

 great pyramids. Taking the principal pyramids at Chizeh, the 

 author states that the lines joining their centres form, together 

 with the meridional and east-to-west lines through them, a system 

 of right-angled triangles whose sides are in simple ratios, e. g. as 

 3:4:5, or as 20 : 21 : 29, &c. Also the sides of these triangles 

 are said to contain each an exact number of a new cubit, styled by 

 the author "E.B. cubit" [query, " Eobert Ballard cubit*"?], so 

 called " because it closely resembles the Eoyal Babylonian cubit :" it 

 seems also that this " E.B. cubit " is exactly one geodetic " third," 

 i. e. -g-^th part of one second of the earth's polar circumference. A 

 new theory is advanced, that the pyramids were intended as a sort 

 of fixed surveying-instrument, viz. as great marks for ranging out 

 lines on definite bearings, and for recovering landmarks lost in the 

 annual inundations of the Nile : this may be so, but they would be 

 a very expensive form of landmarks. A whole chapter is devoted 

 to the advantages to surveyors and engineers of the use of right- 

 angled triangles, especially of the " beautiful triangle " whose sides 

 are as 20 : 21 : 29. Another chapter is devoted to the " beautiful 

 symbol " of the pentangle (or 5-pointed star), which it seems is the 

 "geometric emblem of extreme and mean ratio," and also the " sym- 

 bol of the Egyptian pyramid Cheops " (the pyramid, however, is 

 four-sided). Moreover, if "we close the geometric flower Pentalpha," 

 and thereby " convert it into a pyramid," it appears that " such 

 transitions point to the indissoluble connexion between plane and 

 solid geometry." This work is handsomely got up. 



Allan Cunningham, Major B.E. 



