November 12, 1908] 



NA TURE 



oi 



contents; a thickness of stone doubled (for no reason) 

 and multiplied by the power or logarithm of another 

 quantity to get a lineal quantity; a series of different 

 breadths in inches added together (p. 178) x 10, com- 

 pared with the number of theoretic pounds in a 

 theoretic ton ; or the number of lineal inches in a 

 dimension (p. 187) shown to be the same as the 

 number of grains in a theoretic cubic inch of an 

 arbitrary specific gravity. No rational sense can be 

 attached to such processes ; they are numerical co- 

 incidences, and can have no meaning. When a very 

 large number of quantities, of multipliers, and of 

 processes of connection can thus be handled, and a 

 wide latitude is allowed for the exactitude of the 

 results, there is no reason for the product ceasing 

 at 217 pages; it might as easily be continued to 

 infinity. 



The starting point is the boss of granite — one of the 

 well-known lugs for stone lifting, the remains of 

 many of which may be seen on other stones in the 

 pyramid. The dimensions of this vary from 4-7 to 5-2 

 inches wide, and 0-94 to i.i inches thick, the faces 

 being roughly hammer-dressed. This is then assumed 

 to be exactly five inches wide and an inch thick. 

 It is then assumed that at its junction with the stone 

 face it is 7x5 inches ; though rounded at the top, it 

 is assumed to be rectangular, and an assumed unit 

 of thirty-five cubic inches is deduced, and then used 

 as a basis for pages of subsequent theory. Any one 

 of the certainly wrong assumptions that are made 

 would leave the conclusion entirely in air. But it 

 serves as an efficient basis for an elaborate gnosis, 

 interesting as a revelation of mental method. 



Matters unknown to the author are also elaborated. 

 We read of " those most exact and artistically pre- 

 pared corner sockets," which are really vague and 

 irregular in every part except the truly flat floor. The 

 cubic content of a socket, which is sunk in a wavy, 

 irregular surface of natural rock, is calculated, and, 

 -^2, the cubic inches equal the lineal inches in a 

 theoretic mile. The faces of the pyramid are assumed 

 to be concave in order to fill up the corners of the 

 rock-cut sockets, and many pages of theory result 

 from this assumption ; yet at the north-east corner 

 the drawn line of the base can be seen running 

 some inches within the side of the socket, showing 

 that the face was straight. 



Not only does such wishing serve instead of facts 

 to the gnostic mind, but it may entirely obliterate 

 facts. We read, p. 17, of " the introduction of the 

 French metric system with complete subversion and 

 abandonment of all our hereditary measures." Yet, 

 strange to say, the old English mile is two kilo- 

 metres, the furlong 200 metres, the chain 20 metres, 

 and the fathom two metres, or building yard one 

 metre, within the small uncertainty of our know- 

 ledge; and this system is based on a foot, which was 

 not only known widely in the north back to Roman 

 times, but was known to foreigners in Egvnt for 

 thousands of j'ears earlier. It is curious that the 

 metric system was thus closely anticipated, and it 

 is exactly contrary to our author's statements. 



Points at issue might be raised innumerably, but 

 •so. 2037, VOL. 79I 



it would be useless to do so. The type of mind that 

 is nourished by such material transcends the usual 

 limits of facts and proofs, and remains for us as 

 one of the interesting specimens in the museum of 

 psychology. W. M. F. P. 



THE ANTHRACITE OF SOUTH WALES. 

 The Coals of South Wales, 'with Special Reference to 

 the Origin and Distribution of Anthracite. By 

 Aubrey Strahan and W. Pollard. Pp. vi + 78. 

 Memoirs of the Geological Survey of England and 

 Wales. (London : H.M. Stationery Ofiice, 1908.) 

 Price IS. 6d. 



THIS memoir gives the results of an investigation 

 into the character of the coals of South Wales. 

 The collection of the material was begun in 1901, 

 and the work has now so far progressed as to lead 

 to an opinion as to the relative distribution of anthra- 

 citic and bituminous coals, and as to the origin of 

 the difference between them. The results published 

 include not only the analyses made for the purposes 

 of the investigation by Mr. Pollard, Mr. E. G. 

 Radley and Mr. C. A. Seyler, but also ail previous 

 trustworthy analyses of coal from recognisable seams. 

 The total number of analyses is 203. In each case 

 the particulars given include the local name of the 

 seam, the colliery, the authority, the percentages of 

 carbon, hydrogen, oxygen and nitrogen, the ratio of 

 carbon to hydrogen, the percentages of volatile 

 matter, and ash, the specific gravity, and the fuel 

 ratio or the relation of fixed carbonaceous residue to 

 volatile matter. 



In view of the importance of considering the 

 analyses of each seam separately, it was necessary to 

 correlate, so far as possible, the seams of one part 

 of the coalfield with those of another. The sequence 

 of the seams has consequently received careful 

 attention, and a plate of sections is given showing 

 the position and correlation of the seams. The 

 different bands of the same seam are compared, and 

 the results are given of a comparison of different 

 samples from the same seam in the same locality, as 

 well as of different seams in the same locality. Other 

 chapters deal with the analytical methods employed, 

 with the accuracy of coal analyses and with the classi- 

 fication of coals. 



Of the ten plates accompanying the memoir, five 

 are iso-anthracitic charts designed to show areas of 

 equal anthracitism in each seam or group of seams. 

 The degree of anthracitism of each sample is 

 expressed by the factor representing the relation of 

 carbon to hydrogen. Among previous investigators 

 there is a general agreement that the anthracitic 

 character of the coals in part of the coalfield has 

 resulted from a change effected upon coals which 

 had been originally bituminous. Three explanations 

 of the change have been put forward : — (i) that the 

 anthracitic seams have been more deeply buried and 

 consequently exposed to a higher temperature; (2) 

 that they have been altered by adjacent plutonic 

 rocks; and (3) that they are more affected by slip- 

 cleavage. To these three theories there are serious 



