July 4, 1884.] 



SCIENCE, 



25 



graduated to degrees and fractions thereof, and pro- 

 vided with a vernier reading to three minutes. It 

 can be used, like an ordinary paper or ivory protractor, 

 for hasty plotting, and combines triangles and scales 

 in one instrument. For careful and precise work, it 

 is said to be equal to the best special instrument, and 



to be no higher in price. Mr. E. V. d'Invilliers 



read a paper on some characteristics and the mode of 

 occurrence of the brown hematite (limonite) ores in 

 central Pennsylvania, taking for his field of illus- 

 tration the lower Silurian limestone valleys of Centre 

 county. He described the anticlinal structure of 

 these valleys, and the great erosion, aerial and sub- 

 aerial, which these rocks (six thousand feet thick) 

 have undergone, influencing the position and char- 

 acter of many of the present ore-deposits. He noted 

 three varieties of ore: 1°. The wash and lump hema- 

 tite of the Barrens ; 2°. The true limestone ' pipe 

 ore.' ; 3°. An intermediate transition variety. The 

 first is always associated with the sandy magnesian 

 beds low down in the series of No. 2, or below five 

 thousand feet beneath the overlying Hudson-River 

 slates of No. 3. This class shows rounded ore and 

 flint balls, and tough, barren clay, and are secondary 

 or derived deposits of irregular shape. They have 

 been tested a hundred feet deep, and contain from 

 45% to 53% iron, and .051% to .113% phosphorus. 

 The almost total absence of bisulphide of iron is no- 

 ticeable. The cost of mining is about a dollar and a 

 half per ton. The transition variety was assigned a 

 position in the formation from thirty-five hundred to 

 five thousand feet below the slates. They are char- 

 acterized by a more calcareous clay, are compact, 

 amorphous, liver-colored ores, containing from 40 % 

 to 49 % iron, and from .115% to .365% phosphorus. 

 The pipe ores occur usually higher in the limestones 

 than either of the other two, but in this county 

 below the four hundred feet of upper Trenton layers. 

 These ores occur in situ between parallel walls of 

 limestone, in plate-like masses, scales, or as cylin- 

 drical pipes in bunches eight or ten feet long, while 

 feathering out both in line of strike and dip. The 

 deeper banks show the repeated occurrence of crystals 

 of iron pyrites in all stages of metamorphism. They 

 occur at great depths, and show from 45 % to 53 % 

 iron, and from .100% to .185% phosphorus. The 

 flint or quartz grains accompanying them are rarely 

 water- worn; and this clay is very calcareous and 

 easily washed, not requiring the jigging necessary for 

 cleansing the lower ores. Cost of mining these ores 

 varies from ninety cents to a dollar and a quarter per 

 ton. 



New- York microscopical club. 



June 6. — Rev. J. L. Zabriskie read a notice of Ap- 

 pendicularia entomophila Peck, a new fungus para- 

 sitic on the fly Drosophila nigricornis Loew. The 

 fly, determined by Dr. H. A. Hagen of Cambridge, 

 was noticed at Nyack, N.Y., between the 13th and 

 31st of March last, infested with the fungus. But in- 

 fested specimens have not since been found. In the 

 spring of 1880, three specimens of the same fly, simi- 

 larly infested, were captured at New Baltimore, N.Y. 



These latter specimens were preserved and mounted ; 

 but, from lack of time and opportunity, the true 

 nature of the parasite was not then recognized. The 

 fungus has been submitted to Prof. C. H. Peck, New- 

 York state botanist, who has kindly examined it, and 

 named it Appendicularia entomophila. It is closely 

 related to the Sphaeronemei of the family Coniomy- 

 cetes. Like Sphaeronema, the fruit has a bulbous 

 conceptacle, surmounted by a long beak perforated 

 at the apex, where the spores ooze out in a globule; 

 but, unlike any described Sphaeronema, this has the 

 conceptacle seated upon the broad summit of a pedi- 

 cle as long as the conceptacle itself; and also on one 

 side of the summit of the pedicle and at the base of 

 the conceptacle, it has an erect, leaf-like appendage, 

 with strongly serrate margins, like a white-elm leaf 

 folded along its midrib. The spores are slender, 

 pointed at each end, and divided by a septum into 

 two unequal cells, one cell being twice as long as the 

 other. The total length of the fruit is from .02 to .03 

 of an inch, and that of the spores from .001 to .002 of 

 an inch. The conceptacles of the fungus project di- 

 rectly from different points of the surface of the fly ; 

 so that they are found in all positions, — erect, hori- 

 zontal, and dependent. They grow sometimes singly, 

 but oftener in clusters of two, three, or more, and are 

 found most frequently on the tibiae of the hind-legs, 

 but also springing from the inner posterior surfaces 

 of the abdominal rings, from the costal vein of the 

 wing, from the head, and from the thorax. One of 

 the New-Baltimore flies had about fifty of these con- 

 ceptacles on various parts of the body and limbs. 



NOTES AND NEWS. 



Dr. Gill, has recently paid a visit to the work- 

 shop of the Messrs. Repsold, and gives an account of 

 the great Russian telescope, with several particulars 

 not contained in Professor Newcomb's report ( Sc ience, 

 No. 60). The tube, instead of being cigar-shaped, as 

 in the Washington and Vienna telescopes, is cylindri- 

 cal, and therefore no larger at the centre than at each 

 end. The object of choosing this form is in order 

 that the centre of gravity of the tube may be as near 

 as possible to the polar axis of the instrument. The 

 central part is of cast-iron. The steel plates dimin- 

 ish in thickness from the centre towards the object- 

 glass, so that the whole structure is extremely rigid. 

 In order to get a sufficient field of view, the microm- 

 eter has been made about a foot long. The microm- 

 eter contains a small spectroscope, so arranged that 

 the spectrum of any celestial object can be observed 

 without any change of the instrument. It is expect- 

 ed that the telescope will be mounted at Pulkowa 

 during the coming autumn. Some delay, however, 

 has been experienced in getting the dome into work- 

 ing order, and this may still farther delay the mount- 

 ing of the instrument. 



— A memorial tablet, in honor of the late Professor 

 Charles F. Hartt of the geological survey of Brazil, 

 has been placed in the library of Acadia college, 

 Wolfville, N.S. It was here that Professor Hartt 



