Reviews — J. G. Millais — British Deer. 133 



been to some extent relieved and is less. The recent occurrence 

 of earthquakes along the New Jersey end of this very fault-line 

 shows that the resistance there is less, and that the remaining 

 strain must likewise be less. On sucb a comparatively weak 

 yielding line the rook beds in readjusting themselves, even where 

 ■there is no violent earthquake, must occasion a certain amount, 

 not only of strain, but of friction and heat that might give rise 

 to electrical currents. A decided magnetic effect, too, has sometimes 

 been observed to accompany earthquakes, and in some cases to 

 precede them. In like manner, the strains and yielding or readjust- 

 ment that may be occasioned by the attraction of the sun and moon 

 might apparently cause electrical currents ; and, in fact, magnetic 

 disturbances have been found to correspond, like tides, with the 

 place of those heavenly bodies. Again, the broken or arched 

 form of the rock beds may permit at least a temporary local 

 variation in the temperature of the crust, as affected by the 

 earth's hot interior, that could occasion electrical earth currents. 

 Terrestrial magnetism seems, then, to arise not only from the manifold 

 action of the sun's heat upon the air and the earth's crust, but 

 from the internal movements of the crust and from the tidal 

 effect of the sun and moon upon the air, ocean, and solid earth. 



The author does not admit that the magnetic curves could have 

 been produced by any known deposits of iron-ore or trap, near or 

 distant; comparing such an idea to the ancient Oriental tales of the 

 loadstone that drew men's boot-nails, or the seaside mountain that 

 pulled the bolts out of ships' sides. He adds : — " Deposits of 

 magnetic iron-ore, though differing much in magnetic force, seldom 

 directly affect the most delicate magnetic needle at a distance of 

 more than a few hundred feet." 



12, E "V I S ^\Ar S. 



British Deer and their Horns. By John Guille Millais, 

 F.Z.S., etc. With 185 text and full-page illustrations, mostly 

 by the Author, assisted by Sidney Steel, two by E. Roe, and 

 photographs ; and a series of unpublished sketches by Sir 

 Edwin Landseer. Imp. 4to ; pp. xviii and 224. (London : 

 Henry Sotheran & Co., 37, Piccadilly, and 140, Strand, W.C. 

 1897.) 



(PLATES III AND IV.) 



MR. MILLAIS is already favourably known to the public as 

 the author of " Game-Birds and Shooting Sketches " and 

 " A Breath from the Veldt," both rich in illustrations. Although 

 a thorough sportsman, and, like his father, the late Sir John Everett 

 Millais, Bart., R.A., a born artist, Mr. John Guille Millais com- 

 bines with these qualities sufficient of the true naturalist and 

 palaeozoologist, to lead him in his " History of British Deer 

 and their Horns " to enter upon a brief account of the ancient 

 types of deer which inhabited these Islands in prehistoric times, 



