312 Scientific Intelligence. 



rescent light (this Journal, xxxiii, 307) and obtained the curious 

 result of an image formed by the light from fire flies. A dozen 

 of the fire flies were enclosed in a wide-mouthed vial, in which 

 they emitted their momentary flashes of greenish-yellow light, in 

 the familiar way, stimulated by a gentle shaking. A sensitive 

 bromide dry plate was placed beneath an ordinary glass negative 

 of a landscape, and the vial of insects inverted over the back of 

 the negative. The plate was exposed to the light emitted by 

 fifty of the flashes and then developed ; a distinct positive image 

 of the negative picture was the result, the plate being somewhat 

 yellow stained as if from too long an exposure. — St. Louis Pho- 

 tographer, July, 1887. 



4. Annual JReports of the Board of Directors of the Chicago 

 Astronomical Society, together with report of the Director of the 

 Dearborn Observatory for 1885 and 1S86/ with papers by Pro- 

 fessors Safford (Nebulce), Colbert (Lunar apsides and iSirius), 

 and Hough {Double Star Catalogue, and printing chronograph). 

 Chicago, 1887, pp. 50. — The work with the great equatorial of 

 this observatory has been principally given to difficult double 

 stars and the planet Jupiter. 



5. Professor Pickering has decided to publish short articles 

 upon Astronomical and Meteorological subjects prepared at the 

 Harvard College Observatory as successive numbers of a series 

 which will constitute the 18th volume of the Annals of the 

 Observatory. 



The first article is a table of the magnitudes of the stars used in 

 the various Nautical Almanacs. The table contains 800 stars, and 

 gives their magnitudes derived from the Harvard, the Argentine, 

 the Wolff and the Oxford Photometries. It will be of interest 

 both to regular and to amateur astronomers as an independent 

 catalogue of the brighter stars, and as an index to the stars in the 

 several almanacs. 



The second paper consists of a comparison of the Oxford, the 

 Harvard and the Bonn Uranometries. 



6. Resultados del Observatorio National Argentino en C6r- 

 doba durante la direccion del D or Benjamin A. Gould; Juan 

 M. Thome, Director. Vol. VI, 4°, Buenos Aires, 1887.— This 

 sixth volume contains the Cordoba observations made during the 

 year 1875. The 7th and 8th volumes containing the zone cata- 

 logue have been already published. 



II. Geology and Mineralogy. 



1. Damming and erosion by Greenland ice. — Mr. J. E. Marr, 

 in an interesting paper on the work of ice sheets as illustrated 

 by the Greenland glacier (Geol. Mag., April, 1887), has the fol- 

 lowing paragraphs on the damming of valleys by ice, and the 

 amount of erosion in some valleys. 



The very conspicuous manner in which the Greenland valleys 

 are stopped up by ice is also worthy of notice in connection with 



