NATURE 



[July i, IC09 



of the " sandy desert or barren land," considering 

 that the chilghosa forests of these mountains (which 

 are all about these summits) are of great economic 

 importance to the tribes people who make use of them. 

 It will be observed that these criticisms point, not to 

 the maps of India with which the " Gazetteer " is prin- 

 cipally concerned, but to the maps of the Indian 

 frontier and trans-frontier. Of the maps of India it is 

 enough to say that they are all admirably clear and 

 most instructive, each in its distinct and separate line 

 of illustration; but inasmuch as the frontier is now 

 very rightly included in all works dealing seriously 

 with Indian problems, it is time that the public were 

 supplied with map information of a class equal to that 

 of the Indian peninsula generally. This is not quite 

 the case in this atlas. 



Take, for instance, the map of Baluchistan amongst 

 the " district " series. Were no attempt made at 

 reproducing the orography of that remarkable country 

 the map might pass sufliciently well as a sketch ; but 

 the crude representation of the mountain features 

 which at present disfigures the map is absolutely mis- 

 leading. All the beauty (and it is very beautiful) of 

 nature's arrangement of sweeping flexures and folds 

 which border the trans-Indus highlands ; the orderly 

 curves of their looping up where the inset of the Kach 

 Gandava desert occurs (just like the looped-up flexures 

 in hanging drapery) pushing back and forming the 

 massive mountain entourage of Ouetta ; then sweeping 

 away in graceful flexures seamed with a thousand 

 wrinkles to Karachi, or through Makran to Persia — 

 all this is lost in the graceless disposition of a few fat 

 slug-shaped forms over the yellow surface of the map. 

 This is not the orography of Baluchistan, or Makran, 

 and it is misleading. The traveller who trusted, by 

 following this map, to turn the northern end of the 

 Kirthar range and to walk into Khozdar on the flat 

 plains would be grievously disappointed. The wall of 

 the frontier hills is not even represented as continuous, 

 and even if the scale of the map does not admit of 

 giving full value to many important, but minor, 

 features, there is at least no excuse for fundamental 

 •errors such as this. The map is certainly not over- 

 crowded with names, and this fact renders it all the 

 more desirable that those which exist should be correct. 

 The " Central Makran " range is an invention which is 

 hardly permissible. Not only is it not near the centre 

 of Makran, but it is doubtful whether it is, all of it, 

 even in Makran. As regards the frontier, we must, 

 however, be thankful for small mercies. It is some- 

 thing to find a map of Baluchistan which is correct in 

 its political boundaries, and it is a great deal to find 

 a map of Afghanistan which is in almost every respect 

 a far better illustration of the country it represents 

 than that which we have just criticised. 



The city maps at the end of the series are wholly 

 admirable, and so are the railway maps which precede 

 them. It would hav3 added greatly to the interest of 

 the series could we have had maps of some of the most 

 ancient, and, historically, the most important, of the 

 cities of the past; Chitor, Ujjain, Udaipur, and many 

 another that we could mention, will always possess an 

 undying interest for the student of India. On the 

 NO. 20-0, \OI.. 81] 



whole, this atlas is an admirable addition to the 

 "Gazetteer," and as it is probably the most useful 

 volume for reference in the whole series, so may we 

 hope that in due time it will become the most accurate. 



T. H. H. 



ESSAYS ON LEONARDO DA VINCI. 



Etudes sur Leonard de Vinci, ceux qu'it a liis et ceux 

 qui I'ont hi. By Pierre Duhem. Seconde S^rie. 

 Pp. iv-l-474. (Paris : A. Hermann, 1909.) Price 

 15 francs. 



THIS volume contains four essays, on Leonardo da 

 Vinci's views on the infinitely great and the 

 infinitely small, on his ideas on the plurality of worlds, 

 on his dependence on the philosophy of Nicolaus de 

 Cusa, and on his ideas on the origin of fossils. 



When endeavouring to estimate the value of the 

 notes and jottings of the great painter it is necessary 

 to consider the books accessible to him and the 

 problems under discussion among philosophers of his 

 day. M. Duhem has made a detailed study of the 

 works of mediaeval thinkers, and he traces the develop- 

 ment of the ideas by which Leonardo's mind was 

 influenced, and the advances he made, by which, unfor-, 

 tunately, the world did not profit since they remained 

 locked up ill his note-books. The foundation on which 

 every speculation rested was still the philosophy of 

 Aristotle, viewed in many cases through the spectacles 

 of the scholastics, and often influenced by the com- 

 mentaries of Arabian philosophers. But Leonardo 

 reasoned independently on every subject, and though 

 he often adopted opinions held by his predecessors, he 

 never followed slavishly in their footsteps. This is well 

 illustrated by his attitude with regard to the question 

 whether there might be more worlds than the one of 

 which the earth was the central part, and which was 

 bounded by the starry sphere. Aristotle had denied 

 that there could be more than one universe, because a 

 body can only be at rest in its natural place, so that 

 the earth of a second world would fall down on our 

 earth, and no body can therefore exist outside the 

 starry sphere. The question was a difficult one to the 

 scholastics, because to deny the possibility of the 

 plurality' of worlds seemed to involve denying the omni- 

 potence of God ; but a curious compromise was pro- 

 posed by Albert of Saxony, that if there were another 

 world it would have to be concentric with ours, because 

 the centres of gravity of our earth and the other one 

 would have to coincide if there were to be equilibrium, 

 and this could only be the case if the other earth were 

 in the form of a spherical shell — unless we assume a 

 permanent miracle. L'ndeterred by this, Leonardo in 

 a note considers what would happen if there were, not 

 one, but two centres of gravity. He assumes two 

 worlds of equal size and a heavy body outside the line 

 joining their centres, but at equal distances from these; 

 and he asks how will this body move and where will 

 it come to rest? The answer is that it will move along 

 the perpendicular to the line joining the centres, and 

 be in equilibrium at the po'.nt midway between them. 

 Here, as in many other places, he shows that he had 



