March ii, 1892. J 



SCIENCE. 



151 



precisely the same whether the neck wa& opened or closed. The 

 only work the gas would do in expanding would be that which it 

 did in inflating the balloon, or it would simply displace a volume 

 of gas equal to the enlarged volume of the balloon. It is easy to 

 see that this work would be almost inappreciable. 



It may help to clearness if we consider two balloons suspended 

 by an endless rope passing over a pulley situated at the extreme 

 height to which the balloon rises. This rope has no weight, and 

 there is no friction at the pulley. One of the balloons is at the 

 earth's surface, and the other at the highest point. The system 

 is in equilibrium, and it would require but the slightest weight at 

 the topmost balloon or a diminution of weight in the balloon at 

 sea-level to disturb the equilibrium and cause the balloons to 

 change places. It is very evident that throughout this motion the 

 air sustains both balloons, and the work of expansion in one bal- 

 loon or the work done by the air in compressing the gas in the 

 other balloon would be almost inappreciable. 



In.'^tead of using hydrogen in our balloons we may use heated 

 air and the results of the analysis would be exactly the same. 

 Lastly, we ma.y dispense with our envelope, and simply consider 

 the heated air as rising in the atmosphere. As we have just seen, 

 this air would do very little work, and the consequent cooling 

 would be very slight; the converse would also be true, that the 

 work of diminishing the distance between the molecules of the gas 

 would be very slight, and the heating almost inappreciable so far 

 as the compression was concerned. 



The application of these views, if they shall be sustained, to 

 nearly all theories in meteorology is very obvious. It has been 

 only after the most careful study and analysis of all the questions 

 involved, and a taking up and explaining all the apparent contra- 

 dictions between the older views and these, that I have felt justi- 

 fied in presenting them so much in detail. I bespeak for them a 

 most searching examination and criticism, hoping that thereby the 

 whole truth may be established. H, A. Hazen. 



March 2. 



Pyrite Incrustations of the Cretaceous Formations of Middle- 

 sex County, N.J. 



One would scarcely expect to find beautiful mineralogical 

 specimens in so uninviting a place as a clay pit. The specimens 

 of pyrite incrusting wood and bark, that may be found in most of 

 the clay pits of Middlesex County, N.J., are very beautiful, 

 whether viewed assthetically or as cabinet specimens. The in- 

 crustations as found near Ford's Comers occur in the black and 

 dark-colored clays which usually overlie the lighter and better 

 clays. This dark stratum of clay contains many remains of leaves, 

 twigs, and bark, which have been partially changed into brown 

 coal. Occasionally whole trunks are found which yield wood 

 which ^may be wrought into a variety of ornamental objects 

 which are capable of taking a good polish. As waters containing 

 sulphates of iron come in contact with this carbonaceous matter 

 the carbon unites with the oxygen of the sulphates and sulphide 

 of iron is left in its place. In some specimens the pyrite is found 

 covering the carbon, while in others the carbon has been com- 

 pletely replaced by pyrite; at the same time the forin of the wood 

 is perfectly retained. 



Specimens having the form of twigs not thicker than a lead 

 pencil, and having a fine crystalline surface, are occasionally 

 found. These make very pretty breast-pins when suitably 

 mounted. Some specimens look as though the material of which 

 they were formed had been poured Qut whilst hot, and had spread 

 on cooling much as hot lead doe? when poured out on a flat plate. 

 Many specimens occur in the shape of balls as large as hen's eggs. 

 These are made up of concentric layers of scale-like crystals 

 formed about a nucleus at the centre. As these are exposed to 

 the weather they scale off gradually, sometimes remaining bright 

 until the balls disappear completely, while at other times they 

 turn dark immediately. 



The pyrite weathers very quickly when left exposed to the ac- 

 tion of the air, and the clay waters. If, however, the specimens 

 are collected and washed as soon as they are removed from their 

 native beds, they will remain bright indefinitely. 



Specimens are occasionally found weighing four or five pounds. 

 When the pyrite is exposed to the weather in contact with sand or 

 gravel, as the iron is changed to the ferric oxide it cements sand 

 and gravel together so that very often the resulting conglomerate 

 retains the form of the original lump of wood. Your clay-pitter 

 does not look with a favorable eye on the " sulphur balls," as he 

 calls them, for clay containing much sulphide of iron is worthless 

 for brick-making. 



Of late years large amounts of clay containing iron have been 

 used for making the so called mottled bricks. 



D. T. Marshall. 



Metuchen, N.J., March 2. 



AMONG THE PUBLISHERS. 



The American girl is not slow to grasp a chance. Some time 

 ago The Ladies' Home Journal organized a free education system 

 for girls, and the magazine is now educating some forty odd girls 

 at Vassar and Wellesley Colleges, and at the Boston Conservatory 

 of Music, all the expenses of the gu-ls being paid by the Journal. 



— The March number of Bubyhood contains an article on " Get- 

 ting the Teeth — First and Second," by the medical editor. Dr. L. 

 M. Yale, which corrects certain misapprehensions as to the teething 

 process and the troubles which are popularly supposed to accom- 

 pany it. Similarly helpful medical articles are "The Care of 

 Delicate Children," by Dr. H. D. Chapin, and "Cuts and 

 Scratches," by Dr. H. Power. An alleged " sure cure" for diph- 

 theria is also discussed by a competent writer. Of most general 

 interest, perhaps, is a curious article on " What Shall be Done 

 with Him ? " — an account of a completely unmanageable though 

 not at all vicious boy, which is sure to give rise to considerable 

 discussion. 



— We have received a copy of the American edition of " Long- 

 mans's New School Atlas," the joint work of George G. Chisholm 

 of the Royal Geographical Society and C. H. Leete of the Ameri- 

 can Geographical Society. It contains thirty-eight double-page 

 maps; but in many cases what is numbered as a single map is 

 really a collection of two or three maps. The introductory maps 

 illustrate the various physical and astronomical phenomena of the 

 globe, the climates and vegetation of different regions and the 

 distribution of races and religions, while the remainder of the 

 book is mainly devoted to political geography. There are, how- 

 ever, several special maps illustrating the climate, geology, and 

 industry of the United States and Canada, and one showing the 

 several acquisitions of territory by the United States. Most of 

 the maps are so colored as to show the elevation of the different 

 sections of land above the level of the sea ; which seems to us to 

 be making too much of a very small matter. The selection of 

 maps is very judicious, and the United States does not appear 

 with such overweening importance as it does in most American 

 atlases ; though it receives as much attention as the British Empire, 

 and much more than any other part of the world. The number 

 of towns indicated on most of the maps is small; and though a 

 school atlas ought not to be overburdened with town names, the 

 present work would ha^e been better if it had contained more of 

 them. The maps are well engraved on excellent paper, and as a 

 general atlas of the world for school use, the book is meritorious. 

 It is published by Longmans, Green, & Co. of New York, at one 

 dollar and a half. 



— Professor David Starr Jordan makes the inspiring influence 

 of a great teacher of science strongly felt in the account of 

 " Agassiz at Penikese," with which he is to open the April Popu- 

 lar Science Montlily. The article contains many of Agassiz's own 

 words, which reveal the master's spirit better than pages of de- 

 scription. An authentic account of what treatment the Catholic 

 Church actually gave to Galileo and his discoveries and writings 

 will be given by Dr. Andrew D. White in one of his Warfare of 

 Science papers. Attempts have been made to dispr^ive or explain 

 away much of this ecclesiastical persecution, but Dr. White's 

 statements are fortified by copious citations from authors of un- 

 questioned orthodoxy. The same article tells just how far into 



