y lb 



NATURE 



[February 24, 19 ib 



tilting of the pier and ground. Both these effects are 

 of thermal origin, meteorological conditions modified 

 by the observer's presence being responsible for the 

 former, the latter being due to solar heating. Even in 

 the underground chambers where horizontal pendulum 

 work is carried on, daily oscillations of level due to the 

 sun have been manifested. Prof. Sotome next investi- 

 gates the theory of the motion of the level bubble, the 

 upshot being that the imperfection of the spirit-leve! 

 Is not negligible in zenith telescope observations. It 

 is instructive to note that the errors under investiga- 

 tion are of the order of hundredths of a second of arc ! 

 It is fina-lly concluded that both the "s" term and the 

 "closing sum" would vanish if the spirit-level were a 

 perfect instrument or if it were replaced by means 

 more nearly ideal, such, for instance, as presented 

 by the Cookson floating zenith telescope (Journ. Coll. 

 of Sci., Tokyo, vol. xxxvii., art. 3). 



DINOSA URS. 



THE American Museum of Natural History, New 

 York, has just issued Handbook No. 5, giving a 

 popular and well-illustrated account of the Dinosaurs. 



tion of an Iguanodont Dinosaur, J'/u'SCL'osanrui nii;/ectns, !ri 

 Wyo liing, U.S.A , by Dr. C. \V. Gilmore. Heighi 4 ft.. 



it has been prepared by Dr. W. D. Matthew, and is 

 in large part a reprint of papers already published by 

 himself, Prof. H. F. Osborn, and Mr. Barnum Brown. 

 Prof. S. W. Williston has also contributed an interest- 

 ing historical chapter on the first discovery of Dino- 

 saurs in western North America, in which he himself 

 took a prominent part. There is naturally some repe- 

 tition in the reprints, with occasionally divergent 

 opinions ; but the handbook affords an admirable 

 glimpse of the various groups of these strange Meso- 

 zoic land-reptiles, besides an ample discussion of the 

 theories as to their modes of life. Several of the Beau- 

 tiful illustrations are only accessible elsewhere in 

 technical memoirs, and Dr. Matthew has added some 

 new synoptical diagrams which will be useful to 

 students. 



A small bipedal Dinosaur related to the familiar 

 laruanodon, and almost identical with the Engfish 

 Wealden H3'psilophodon, has been discovered in the 

 Upper Cretaceous Lance Formation of Wyominir, 

 U.S.A. The greater part of a skeleton, lacking only 

 the skull and neck, has lately been uncovered in a 



NO. 2417, VOL. 96] 



slab of rock in the United States National Museum 

 and is described by Dr. C. \V. Gilmore in No. 2127 

 of the Proceedings of that museum. The bones lie 

 almost in their natural position, and Dr. Gilmore has 

 wisely decided to leave them undisturbed in the matrix. 

 There are also slight traces of the skin, with fine 

 epidermal tubercles, but no dermal ossifications. The 

 reptile is named Thescelosauriis neglectus, and when 

 restored with the head and neck of Hypsilophodoii 

 foxi, appears as represented in the figure which we 

 copy from Dr. Gilmore's paper. In this attitude i1: 

 would measure about 4 ft. in height, and it is obviously 

 of very agile proportions, adapted for rapid running. 



VENTILATION OF SOILS. 



THE relation of soil gases to crop production has 

 received considerable attention during the past 

 year, notably in India. In Bulletin No. 52, issued 

 by the Agricultural Research Institute, Pusa, Mr. 

 and Mrs. Howard discuss the ventilation of soils in the 

 great alluvial plains forming the Ganges basin and 

 in the Quetta valley of north-west India. The authors 

 think that, in a country like India, where water is so 

 often the limiting factor in crop production, too little 

 attention has been paid to the im- 

 portance of continuous gaseous inter- 

 change between the soil and the 

 atmosphere during the growing 

 period. The conclusions reached in 

 this paper are not based on direct 

 experiment, but on long-continued 

 and almost daily observations 

 on the growth of crops. Antici- 

 pating criticism on the lack of 

 what they term " test-tube evidence," 

 the authors point out that the great- 

 est advances in British agriculture, 

 both as regards crop production and 

 the improvement of stock, have been 

 made by similar methods. 



Having reviewed in detail the 

 agricultural factors of the Bihar dis- 

 trict, the phenomena of growth of 

 the more important field crops and 

 trees are briefly described. A large 

 number of examples are given to 

 illustrate the advantage derived by 

 various plants from a free air supply 

 to their root systems. The 

 chief object of the cultivator 

 of these alluvial soils should 

 be to increase porosity and, in the absence of farm- 

 yard manure, green manuring or the use of broken 

 brick or tile is recommended. The latter method re- 

 quires less cultivation. 



Similar observations are recorded in the Quetta 

 valley, where both climate and soil differ consider- 

 ably from those of the Bihar district. Under condi- 

 tions of artificial irrigation the flooding of the land 

 tends to pack the soil and cut off the supply of oxygen 

 to the plant roots. It is claimed that the principle of 

 more air and less water will not only yield a greater 

 crop, but result in a valuable saving of irrigation 

 water. The paper concludes with a reference to the 

 ecological aspect of soil aeration as shown by the dis- 

 tribution of the gram-growing areas of India. This 

 plant requires a great deal of air, and only a moderate 

 amount of water. Wherever it is successfully grown 

 the soil and system of cultivation are favourable to 

 root aeration. The authors are to be congratulated on 

 their systematic collection of data, which show clearlv 

 the importance of controlling the relation between air 

 and water in the soil. 



m th= Uj.per Ci 

 length 10 ft. 



