296 



NATURE 



[July 28, 1892 



or mud, are brought prominently under notice by a recent 

 reported discovery in Wyoming. This is said to be nothing 

 less than the disentombment of an entire skeleton of that 

 stupendous Dinosaur known as the Brontosaur, in which 

 not only is every bone in place, but an actual mould of 

 the surface of the eye, formed in the sand upon which 

 the creature lay, has been preserved in the solid rock. 



Prof Marsh's restoration of the Brontosaur — a creature 

 60 feet in length, walking on all fours, with an enormously 

 long neck and tail, a disproportionately small head, and 

 the bony substance of its backbone reduced to a mere 

 shell and a honeycombed interior — has been long before 

 the world. Less known, however, is his later reconstruc- 

 tion of the skeleton of one of the gigantic horned 

 Dinosaurs from the Laramie Cretaceous, which he calls 

 Triceratops ; the skull and pelvis of which were referred to 

 in an earlier number of Nature. In this restoration the 

 Professor has certainly succeeded in producing a most 

 marvellous animal, although, so far as we see, the figure 

 appears to be true to nature. It will be remembered 

 that one of the most remarkable features in the skull 

 of Triceratops (which in some specimens was upwards of 

 12 feet in length) is the production of the hinder regi on 

 into a huge fan-like shield, the use and purpose of which 

 it was at first a little difficult to understand. This is, 

 however, explained by the restored skeleton, where we 

 see this shield overlapping and protecting the first six 

 vertebras of the neck ; to which additional strength was 

 imparted by the bony union of several of them. In the 

 shortness of its neck and the enormous size of its skull, 

 Triceratops presents a striking contrast to Brontosaurus. 

 Like the latter, however, it habitually walked on all 

 fours ; while in correlation with its massive skull its fore- 

 limbs were relatively stouter than in any other Dinosaur. 

 In this respect it differs widely from its near ally, 

 Stegosaurus, which, at least occasionally, walked in a 

 bird-like manner ; and since Triceratops is evidently a 

 more specialized creature than Stegosaurus, the sugges- 

 tion arises that the former has undergone a retrograde 

 development from a bipedal to a quadrupedal mode of 

 progression. No attempt has yet been made to represent 

 the position on the skeleton of the dermal bony armour 

 with which many parts of the body of Triceratops were 

 protected during life ; the precise position of the various 

 spines, knobs, and plates, which have been found in 

 association with the bones, being largely a matter of 

 conjecture. The size in life of the restored example 

 would be approximately some 25 feet in length by 10 

 in height ; but these dimensions must have been exceeded 

 by other specimens. 



By the completion (so far as anything connected with 

 fossils can be said to be complete) of our knowledge 

 of the skeleton of Triceratops, we are acquainted with 

 the bony framework of all the chief types of Dinosaurian 

 reptiles at present known. These may be classed as the 

 Sauropodous type, as represented by Brontosaurus ; the 

 Theropodous type, as represented by Megalosaurus and 

 its allies ; and the Ornithopodous modification, repre- 

 sented on the one hand by Iguanodon, and on the other 

 by Stegosaurus, Triceratops, &c. 



In the contemporary publication to which we have 

 referred some interesting suggestions as to the probable 

 habits of these Dinosaurs are put forth, although how far 

 they will meet with acceptation remains to be seen. Thus 

 it is suggested that the honeycombed vertebras of the 

 Brontosaurs and their allies were filled with warm air 

 from the lungs (which assumes that these reptiles were 

 warm-blooded), by which means their bodies were partly 

 floated when they wandered out of their depth in the sea 

 shallows, from whence they stretched their long necks to 

 crop the seaweed near the shore. Again, the long hind 

 legs of the Hadrosaur (an ally of our Iguanodon) are 

 considered to have enabled their owner to wade far out 

 to sea in search of seaweeds growing on the ocean- 



NO. 1 187, VOL. 46] 



floor ; while the armoured kinds, like Stegosaurus and 

 Triceratops, are considered to have been essentially 

 terrestrial. 



As we have indicated, the great bulk of the collection is 

 composed of Secondary reptiles and Tertiary mammals ; 

 and from their large size it is these which form its most 

 striking feature. We most not omit to state, however, 

 that it also contains the Toothed Birds from the 

 Cretaceous of Kansas (of which our English collections 

 do not at present possess a single bone), as well as 

 hosts of teeth of Mesozoic mammals, although we have 

 no definite information as to what proportion of these 

 are the property of the State, and what belong to Prof. 

 Marsh. Then, again, scattered among the trays and 

 drawers more especially devoted to the remains of 

 mammals and reptiles is an extensive collection of fish- 

 remains from Cretaceous and Tertiary strata, and 

 especially from the Green River Eocene shales of 

 Wyoming, most of which we believe to be at present 

 totally undesc'ribed. 



Space prevents us from saying more as to the extent 

 of this marvellous collection — a collection which, with 

 others from the same regions, has done more in ten 

 years to revolutionize our classifications, and to give us a 

 definite knowledge of many groups of animals previously 

 known by battered fragments, than would have resulted 

 from half a century's work upon European rnaterials. 

 We may, however, conclude by offering our hearty con- 

 gratulations to the Governments of the United States and 

 to Prof Marsh, who have succeeded, by the liberality 

 of the one and the untiring energy of the other, in amass- 

 ing this magnificent collection, which is now, for the first 

 time, in a fair way to be exhibited in a manner befitting 

 its value and importance. Prof Marsh's magnificently 

 illustrated monographs on the Toothed Birds and the 

 Dinocerata are splendid examples of how a collection 

 like this ought to be made known to the scientific world 

 at large ; and we trust ere long to be able to welcome his 

 long-promised volumes on the Dinosaurs and the Bronto- 

 theres, which will render its riches yet better known. 



R. Lydekker. 



D YNA MO-ELECTRIC MA CHINER Y} 



THIS is the first part of a treatise dealing with 

 dynamo-electric machinery and its applications, 

 and comprises the theory and practical construction of 

 dynamos and motors, and an account of instruments and 

 methods of electrical measurement. Such subjects as 

 the fusion and welding of metals by electricity and the 

 transmission of power are reserved for a second part, to 

 be issued in the autumn of the present year. 



The author begins with a chapter entitled " Generali- 

 ties regarding Dynamos," in which he discusses the 

 early rudimentary magneto-machines of Pixii and Clarke, 

 and the multipolar machines of the same class invented 

 by Stohrer and Niaudet, gives a general explanation of 

 the self-excitation and action of series of shunt and com- 

 pound dynamos, and describes the various typical forms 

 of armature used in constant and alternating-current 

 machines. In this part there is room for little novelty of 

 treatment ; the author could only endeavour to be im- 

 partially historical and clearly descriptive, and give as 

 complete and useful an account of the more important 

 examples of dynamo machinery as his space would admit 

 of In this Signor Ferrini seems to have succeeded very 

 well. He does not weary his readers with descriptions of 

 mere antiquities, but supplies only such a brief account 

 of earlier forms as is sufficient to enable the reader to 

 trace the evolution of the modern constant-current 

 dynamo, with its beautiful balance and inter-relation of 



I " Recent! Progress! nelle Applicazioni deil' Elettricita di Rinaldo 

 Ferrini." Parte Prima : Delle Dinamo. (Milano : Ulrico Hoepli, 1892.) 



