September 15, 1S93.] 



SCIENCE. 



^45 



but shows that there can be no middle ground between 

 the common estimate of the plant and that which a log- 

 ical interpretion of all the facts now disclosed forces 

 upon us. 



Each successive season a fresh series of analyses and 

 practical tests were made and j)ut upon record, beginning 

 with that stage of the development of the plant, when the 

 percentage of cane sugar had previously been supposed 

 to have reached its maximum, and extending them 

 through the after period of juice-ripening, brought on by 

 the timely sejjaration of the immature grain, up to the 

 time of frost. It was found that the saccharine strength 

 of the juice, under the new conditions, constantly increased 

 in a fixed ratio, and that the life of the plant was pro- 

 longed from a month to two months beyond the natural 

 period. 



(To be continued.) 



THE ASTEONOMICAL EXHIBITS AT THE WORLD'S 

 FAIR. 



The Astronomical Exhibits at the World's Pair at Chi- 

 cago represent fairly well the present state of the science 

 of astronomy. But they are scattered about in the vari- 

 ous buildings so as to make it difi&cult even to find them 

 all, to say nothing of systematic study and comparison of 

 them one with another. In a general way, the most 

 important astronomical displays are to be found among 

 the educational exhibits, which are located in the west 

 and south galleries of the Manufactures and Liberal Arts 

 Building. In the exhibit of Harvard University, in the 

 south gallery, is a splendid collection of astronomical 

 photographs made by the Harvard College Observatory. 

 Especially interesting are several photographs of stellar 

 spectra and of nebulae and clusters. One photograph of 

 a portion of the moon's disk represents an enlargement of 

 over one thousand diameters. Nowhere else can be found 

 a better illustration of the great usefulness of photog- 

 raphy in astronomy. The collections of Draper and 

 Langley are to be found in the exhibits of the University 

 of the City of New York and of the Western University of 

 Pennsylvania. The four-inch almacantar, which is the 

 first one constructed and used by Dr. Chandler, is in the 

 exhibit of De Pauw University. The exhibit of Johns 

 Hopkins University contains a tine collection of diffrac- 

 tion gratings and photographs of spectra by Professor 

 Rowland. In the German Educational Exhibit, in the 

 west gallery, are specimens of the famous Jena optical 

 glass, the original spectroscope of Kirchhoif, and some 

 fine mathematical models by Brill. Here is also shown 

 the magnetic apparatus of Gauss and Weber. Near by, 

 in the English Exhibit, is the display of the Royal Astro- 

 nomical Society, containing a large number of astronom- 

 ical photographs by Roberts, Gill and Abney, and still 

 others from the Royal Observatory at Greenwich. Boed- 

 dicker's drawings of the Milky-way and Dr. Common's 

 five-foot glass speculum are in the English exhibit. The 

 latter is unsilvered and has evidently been placed with 

 greater care to secure safety than visibility. In the 

 Swiss Exhibit, in the main aisle of the Manufactures Build- 

 ing, is a display of instruments by La Societe Genevoise. 



The exhibits of the American makers of astronomical 

 instruments are in the north gallery of the Manufactures 

 Building, just over the main aisle. Warner and Swasey 

 show a fine twelve-inch equatorial telescope, with smaller 

 instruments, and also the mounting of the great forty-inch 

 Yerkes telescope, which is set up at the north end of the 

 main aisle. The appearance of the great telescope gives 

 an impression of symmetry and strength. The lens for it 

 is being made by Alvan Clark & Sons, of Cambridgeport, 

 Mass. They report satisfactory progress, but say that it 



will not be finished for a year or more. The Clarks, by 

 the way, make no exhibit at Chicago. J. A. Brashear, of 

 Allegheny, Pa., exhibits the stellar spectroscope for the 

 Yerkes telescope. He also shows an eighteen-inch and a 

 fifteen-inch objective, gratings, specula, etc. G. N. Saeg- 

 muller, of Washington, exhibits a variety of instruments 

 of precision, among which are a nine-inch equatorial tele- 

 scope and a four-inch steel meridian circle. The exhibit 

 of the Gundlach Optical Company also deserves mention. 

 The American instrument-makers, as a whole, make a 

 most creditable showing. The displays of the foreign 

 instrument-makers are, many of them, located in the Elec- 

 tricity Building. Schott und Genossen, of Jena, show a 

 large number of specimens of optical glass, and among 

 them are two twenty-three-inch discs of the celebrated 

 Jena glass. Merz, of Munich, shows two equatorial tele- 

 scopes and several telescopic objectives, the largest of 

 which is ten inches in diameter. The Repsolds, of Ham- 

 burg, seem not to be represented — a fact much to be re- 

 gretted. 



Dr. GiU's interesting stellar photographs are in the 

 Cape Colony Exhibit in the Agricultural Building, and the 

 Lick Observatory display is in the educational depart- 

 ment of the California State Building, and is strangely 

 enough mixed up with the kindergarten exhibit there. 



The U. S. Naval Observatory Exhibit is a small observ- 

 atory located northeast of the Government Plaza, and is 

 in charge of Lieut. A. G. Winterhalter, U. S. N. There 

 are a small equatorial telescope, photoheliograph and 

 many smaller instruments. The Weather Bureau Exhibit, 

 a short distance to the west, is well worth a visit. The 

 exhibit of Coast Survey apparatus, in the U. S. Govern- 

 ment Building, is full of interest, from the geodetic stand- 

 point. 



SCIENCE TEACHING IN SECONDARY AND PRI- 

 MARY SCHOOLS. 



DE. GEO. G. GBOrr, LEWISBDEG, PA. 



It has long been a dream of scientists that the time 

 would come when the elements of natural history and of 

 the physical sciences would be taught in secondary and 

 primary schools. To thinking people it does not seem 

 necessary to argue that every boy should be instructed 

 in the elements of chemistry, natural philosophy, botany, 

 geology, zoology and physiology. To persons not teach- 

 ers, it would seem no difficult matter to find a place in 

 the school curriculum for the elements of the above 

 sciences. But it remains true that they are not taught, 

 or taught to such an extent, and in such a manner, as to 

 produce results entirely worthless. 



Why is this condition of things prevalent ? Why, after 

 all that has been said and written, is there is no change 

 for the better ? The answer seems to be this: The ele- 

 ments of the sciences are not taught in elementary and 

 primary schools for the reason that the teachers them- 

 selves have never been taught, and without instruction 

 they feel that to attempt to teach these branches they 

 would be blind leaders of the blind. More than this, the 

 schools whose special duty it is to train teachers for 

 primary and secondary schools, have not begun to do any 

 real work in the line of science instruction. The sciences 

 in these schools are so placed in the background that 

 practically no training at all is given in them. It is then 

 no wonder that the graduate of such a school does not 

 feel capable of giving any instruction in even the elements 

 of the sciences. To demonstrate the above statements 

 the catalogues of the Pennsj'lvania State normal schools 

 will be examined, and certain results tabulated. It will 

 be seen that the teachers of arithmetic and grammar far 



