April 24, 1896.] 



SCIENCE. 



641 



that the local causes of error were diminished 

 to a degree consistent with the desired standard 

 of accuracy. In illustration of the difficulties 

 overcome, it was stated that while a current 

 passing throvigh the bolometer is something 

 like rV ampere, and while a current of less than 

 j^^ millionth part of this will cause a deflection 

 of a millimeter on the scale, no such deflection 

 was visible in the automatic trace shown in 

 illustration. The bolometer was nearly as 

 sensitive at the time of the last communication 

 as it has been made since, and the work of the 

 past two years has lain in guarding this sensi- 

 tiveness against local causes of error, so that it 

 shall be engaged in legitimate service, and re- 

 spond only to a message from the sun. The 

 speaker trusted that the final results of this 

 labor would soon be made public, and con- 

 cluded by renewing a statement of his obliga- 

 tion to those gentlemen who had been pre- 

 viously connected with the work, and by an 

 expression of his indebtedness to Messrs. 

 Abbot, Child and Fowle, who are associated 

 with its present development. 



Me. E. D. Preston read a paper on French, 

 ■German and English systems of shorthand 

 writing, in which he gave a brief review of short- 

 hand writing from the time of the ancient sys- 

 tems down to the present day. The principles 

 underlying the art were illustrated by examples 

 from the French '(Duploye) German (Gabels- 

 berger) and English (Pitman). A comparison 

 was made with reference to accuracy and 

 rapidity in the three cases. Special contrac- 

 tions depending on the particular language em- 

 ployed were also illustrated. As a further test 

 in order that no advantage should be given to 

 •either, each of the systems was applied to a 

 strictly phonographic tongue (Polynesian) out- 

 side of the Indo-European family of languages: 

 The conclusion was that English shorthand is 

 the most philosophical, the French the simplest, 

 and the German the most vigorous. 



Mr. R. a. Harris, of the U. S. Coast and 

 •Geodetic Survey, read a paper the objects of 

 which were ' ' To show in a non-mathematical 

 way what simple oscillations go to make up the 

 complex tidal wave ; to give a short account of 

 the harmonic treatment of tides, and to describe 

 briefly certain mechanical aids which are, or 



may be, used in connection with the analysis 

 and prediction of tides. ' ' 



The principal tidal components were pointed 

 out by considering what their ' speeds ' must 

 be in order to cause them to gain or lose one 

 oscillation on a component having a ' speed ' 

 eqlial to the apparent diurnal motion of the 

 moon or sun, or twice this motion, after the 

 the lapse of certain times, as a tropical month 

 or year, an anomalistic month or year, a half 

 tropical nionth or year, a half synodical mouth, 

 etc. 



A sample was shown of the perforated sheets 

 devised by Mr. L. P. Shidy, of the Survey, and 

 styled 'stencils,' which have been in constant 

 use for upwards of ten years. They indicate 

 how the hourly heights are to be combined in 

 the various kinds of summation, and so do away 

 with the necessity of copying and reeopying the 

 tabular values. 



A design of an adding apparatus to be gov- 

 erned by a stencil sheet embracing, side by side, 

 all components to be summed for was shown. 

 This, if constructed, would enable a person to 

 sum simultaneously for all components almost 

 as rapidly as for a single one upon au ordinary 

 adding machine. The stencil sheet does away 

 with the necessity of the great variety of gears 

 (representing 'speeds') found in the Thomson 

 harmonic analyzer, and insures positive work- 

 ings. In fact, there are but two kinds of gear 

 wheels in the adding apparatus, one containing, 

 say, 300 teeth each, and the other, serving as 

 counters, containing 299. The number of 

 wheels in each of these two sets is 24 times the 

 number of components to be summed for. Each 

 54 partial sums thus obtained are then to be 

 analyzed in the usual way. 



Brief mention was made of the predicting 

 machines already constructed, and comparisons 

 were made with the one now being built by the 

 Survey. Bernard R. Green, 



Secretary. 



GEOLOGICAL SOCIETY OF WASHINGTON. 



The meeting of this Society of April 8th was 

 devoted to a general discussion of the subject 

 of the application of stratigraphy and paleon- 

 tology in determining subdivisions of geologic 

 time. 



