THE MATHEMATICAL GAZETTE cen tre a n d a x is are a p o in t on th e a b so lu te con ic a n d th e ta n g e n t th e r e . P a r t I I , o c c u p y in g o n ly th e la s t fifth o f th e b o o k , d e a ls w ith real p r o je c tiv e g e o m e tr y in te rm s o f fiv e p r im itiv e c o n c ep ts: p o in t, lin e, p la n e, a n d th e r e la tio n s o f in c id en ce a n d se p a r a tio n {w h ich is c a lle d " d iv isio n " ). C o n siste n c y a n d c a te g o r ic ity are e s ta b lish e

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... d b y m e a n s o f h o m o g e n e o u s co o rd in a tes. T h e n th e r e is a lo n g d ig r essio n o n cir cle s a n d e llip se s in p r e p a r a tio n for th e " H ilb e r t m o d e l" w h ic h , a s a n in sta n c e o f a n o n -D e sa r g u e sia n p la n e, is far m ore c o m p lic a te d th a n M o u lto n 's. (S ee, e .g . G. d e B . R o b in so n , T h e f o u n d a ti o n s o f g e o m e tr y , U n iv e r s ity o f T o ro n to P re ss, 1959, p p . 1 2 6 -1 2 8 .) T h e b o o k is b e a u tifu lly p r in te d , w ith 327 e le g a n t figu res a n d a n in d e x o f sy m b o ls a s w e ll a s a gen era l in d e x . A p p a r e n tly th e , o n ly se r io u s m isp r in t n o t n o te d on th e "E r r a ta " sh e e t is o n p a g e 263, w h er e se n te n c e S 4 ap p ears tw ic e a n d se n te n c e S5 n o t a t all.