258 



SCIENCE. 



[Vol. XVII. No. 431 



SCIENCE: 



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SORGHUM AND SUGAR BEETS IN KANSAS. 



The Agricultural Experiment Station at Manhattan, Kan., lias 

 been engaged for tbree years in a series of investigations upon 

 sorghum, the principal aims being: (a) the attempt to find better 

 varieties of sorghum for producing sugar; (b) to improve well- 

 known and approved sorts; (c) to secure both early and late ma- 

 turing kinds of good quabty, especially the former, in order to 

 lengthen the working season. 



Bulletin 16 of this station, for December, 1890. gives the results 

 of this work for 1890, including comparative tests of a large 

 number of varieties, with analysis of their juice; attempts to im- 

 prove seed by selection, trials of fertilizers, and a study of smut 

 in sorghum. The same station has also established a series of 

 experiments in the comparative culture of sugar beets, the results 

 of 1890 being given in the bulletin referred to. The season was 

 unfavorable to both sorghum and sugar beets, on account of both 

 heat and drought. 



Following is the station's summary of the results obtained as to 

 sorghum. 



1. The season of 1890 was very unfavorable to sorghum, owing 

 to deficient rainfall and intense heat during the early summer, 

 followed by cool, wet weather, culminating in an unprecedented 

 killing frost Sept. 13. This frost was so exceptional as to date, 

 and so erratic in distribution, its limit bearing no relation to 

 isotherms or latitude, that it gives no ground for the conclusion 

 that it was too far north for successful sugar manufacture from 

 sorghum. Notwithstanding this, the tables show that the stan- 

 dard varieties maintained a good, though lower, standard of ex- 

 cellence. 



3. The selection of seed with a view to improvement of varie- 

 ties was almost wholly prevented by the early frost. A compari- 

 son of the results obtained for three years in selection of specially 

 good canes lends encouragement to the hope that the standard of 

 sugar-content may be permanently raised by this means. 



3. A comprehensive experiment to test the effect of fertilizers 

 on sorghum has shown no marked results this year, as was to be 

 expected in view of the conditions of growth. The experiment 

 will be continued from year to year, the same fertilizers being 

 applied to the same plat throughout. 



4. In view of the occurrence of two varieties of smut in the 

 plats this year, caution in the inti'oduction of new varieties is 

 urged, lest destructive contagious diseases be brought in at the 

 same titne. 



5. Crossing of varieties deteriorates the crop, so far as the ex- 

 periments have gone. 



The results of the experiments with sugar beets are as follows. 



1. The sugar beets grown do not appear to be of as good quality 

 as those reported to have been produced in other parts of Kansas 

 and in Nebraska. This may have been due to the unusually un- 

 favorable climatic conditions of last summer, or to unsuitability 

 of soil. 



2. Analysis of individual beets indicated that maturity, more 

 than size, determined the sugar-content of the beet. A brown 

 epidermis accompanied high per cent of sugar. As far as the ob- 

 servations went, a high weight of leaves, as compared with the 

 roots, was no evidence of high sugar-content, but rather the re- 

 verse. 



THE MERCURIAL PRESSURE-GAUGE ON THE EIFFEL 

 TOWER. 



The new mercurial pressure-gauge devised by M. Cailletet and 

 erected at the EifEel Tower is an instrument of much scientific 

 interest. The only instruments by which high pressures in gases 

 or liquids can be registered with accuracy are very long vertical 

 pressure-gauges. A gauge of this type, more than three hundred 

 feet in height, was set up by M. Cailletet some years ago, first on 

 the side of a hill, and afterwards in an artesian well. Several 

 scientific men imitated this method of gauging high pressures, but 

 the difficulty of handling and experimenting upon an instrument 

 under conditions so unfavorable, threw considerable doubt upun 

 the accuracy of the results obtained. The Eiffel Tower afforded 

 a unique opportunity for setting up a pressure-gauge 984 feet high, 

 every part of which should be accessible and open to observation. 

 Thanks to the liberality of M. Eiffel, says Engineering, the task of 

 constructing and fixing an instrument on so gigantic a scale has 

 actually been now accoaaplished. 



With a gauge of this height pressure up to four hundred atmos- 

 pheres can be obtained, but it is manifestly impossible to use the 

 customary glass tube. Recourse has. therefore, been had to a 

 tube of soft steel of about one-sixth of an inch internal diameter, 

 connected at the bottom of the tower with a reservoir containing 

 mercury. By pumping water into the reservoir, the mercury in 

 the tube can be gradually raised to the top of the tower. 



A difficulty, however, arose from the slanting position of the 

 columns supporting the tower, which prevented the tube being 

 vertical. From the base of the tower to the first platform, a 

 height of about 197 feet, the tube was therefore placed against the 

 inclined plane of one of the rails of the lift, an iron staircase run- 

 ning beside it. Between the first and second platforms, which 

 are separated by about the same interval, the apparatus was fixed 

 to one of the helicoidal staircases. As this staircase is divided into 

 several sections, ilot in the sajne vertical plane, on account of the 

 obliquity of the column, the tube is similarly divided, and bends as- 

 it passes from one staircase to the other. sufQcient slope being al- 

 lowed for the descent of the mercury when the pressure is reduced. 

 From the second platform to the top the tube is arranged in the 

 same way, following the two vertical staircases, and is thus easUy 

 accessible from top to bottom. 



The steel tube bemg opaque, the level of the mercury cannot be 

 directly read off. Cocks with conical screws, each communicating 

 with vertical glass tubes, are arranged at equal distances, about 

 every ten feet, parallel with and alongside the tube. Each glass: 

 tube hasa scale, carefully marked off on polished wood, which 

 has been selected because it is very slightly affected by changes of 

 temperature. It is adjusted by a rubber band to the metal fram- 

 ing, and leather rings compressed by a screw keep the cock tight. 

 When one of the cocks is opened the interior of the steel tube is 

 placed in communication with the corresponding glass tube. As 

 the mercury rises in the steel tube, it penetrates into and acquires 

 the same level in the glass tube alongside. 



From the bottom of the tower to the first platform, the steel 

 tube, as already mentioned, is in an inclined position, and the 

 series of glass tubes placed vertically across it. These sections of 

 glass tube are about ten feet long, each furnished with its scale 

 and the cock communicating with the main steel tube; thus the 

 pressure in any given glass tube is limited to its length of ten feet. 

 The scales are marked in metres and centimetres, so that the head 



