May 13, 1892.] 



SCIENCE. 



275 



ASTRONOMLCAL NOTES. 



[Edited by George A.iHill,] 

 Comet a, 1892. 



The following ephemeris of comet a, 1892, is from a hyper- 

 bolic orbit computed by Father G. W. Searle of the Catholic 

 University, and is based upon observations made on March 

 10, March 29, and April 22, and represents very closely an 

 observation made by Father Searle on the morning of May 

 6. The epoch is for Greenwich midnight : — 



R.A. 



Dec. 



0.1270 



0.1329 



0.1387 



0.1444 



0.1499 



0,1553 



0.1657 



0.1707 



1756 



Br. 



0.61 



0.55 



0.52 



0.49 



0.46 



0.44 



0.42 



0.40 



0.38 



Winnecke'e Perodic Comet. 

 Ephemeris continued from No. 482 of Science: — 

 R.A. Dec. 



Bright Streaks on the Moon. 

 Professor Holden in No. 22 of the Publications of the As- 

 tronomical Society of the Pacific calls attention to an inter- 

 esting question in regard to the system of bright streaks on 

 the moon, which radiate from the craters Tycho, Copernicus, 

 Kepler, and others. These streaks, as he says, are well 

 known objects, and are depicted upon the maps of the moon 

 made by Lohrmann, Beer, and Maedler and Schmidt. Pro- 

 fessor Holden offers to place at the disposal of any one who 

 has the time to devote to the research, glass-positives of the 

 moon taken with the great telescope. What is desired is to 

 compare the photographs with the best maps to see if these 

 bright streaks shift as the moon's age varies, or if they are 



fixed. Professor Holden's kind offer should be accepted by 

 some one who has the time to give the subject careful con- 

 sideration, as it is not at all diificult and only needs a good 

 supply of patience. 



Astronomy and Astro-Physics for May. 



Astronomy and Astro-Physics for May contains some 

 very interesting papers. Professor W. H. Pickering describes 

 the mountain station of the Harvard College observatory at 

 Arequipa, Peru, at an attitude of 8,055 feet above the sea. 

 Professor Pickering states that a power of 1,140 on tl^e 13- 

 inch telescope has been used upon Venus in the daytime, 

 that power showing the planet to a decidedly better advan- 

 tage than 812. The phases of Jupiter's satellites are readily 

 observed as they enter the shadow of the planet, a phenome- 

 non very seldom seen in low altitudes. Professor Pickering 

 sums up the advantages derived from his station in these 

 words, ■' What we see here depends not, as elsewhere, upon 

 the condition of the air, but only upon the size and quality 

 of the telescope employed." 



Mr. J. A. Brashear gives a sketch of the life of G. B. Clark, 

 the great optician. Mr. T. J. J. See links together the his- 

 tory of the color of Sirius. Professor Barnard gives the re- 

 sult of his successful attempt to photograph Swift's comet. 

 Mr. Monck writes on the Spectra and Proper Motion of Stars, 

 and Professor Vogel, on the Motion of Nova Aurigse in line 

 of sight. Mr. Cortie has Some Recent Studies on the Solar 

 Spectrum. Solar Photography at the Kenwood Astro-Physi- 

 cal Observatory is treated by Professor Hale, and Professor 

 Pickering writes on The Nova in Aurigie. Other interesting 

 papers follow, besides news and notes of interest to astrono- 

 mers. Professor Payne and Professor Hale have made a 

 most interesting number in the one that is now before us, 

 and we hope that their endeavors will not be abridged in the 

 future. 



IS IT DANGEROUS TO SPRAY FRQIT-TREES WITH 

 SOLUTIONS OF POISONOUS SUBSTANCES IN 

 ORDER TO PREVENT DEPREDATIONS FROM 

 DESTRUCTIVE INSECTS? 



The following report of experiments made to determine the 

 amount of copper and arsenic adhering to fruit that had 

 been sprayed with Bordeaux mixture and other compounds 

 is taken from Bulletin 17 of the Hatch Experiment Station 

 of the Massachusetts Agricultural College at Amherst. 



Grapes. 



During the early autumn the Board of Health of New 

 York City condemned several carloads of grapes as danger- 

 ous to the public health and ordered them destroyed, because 

 they were slightly disfigured with the Bordeaux mixture 

 which had been used by the growers to prevent mildew and 

 rot. This caused a "scare" among the dealers and con- 

 sumers and a serious fall in prices, which affected the market 

 more or less for the rest of the season. To determine posi- 

 tively the amount of copper adhering to the grapes grown in 

 the college vineyard, two lots of fruit, of ten pounds each, 

 were selected, one from vines sprayed with the Bordeaux 

 mixture throughout the season, and which were very badly 

 disfigured, and the other from vines that were treated with 

 the Bordeaux mixture up to the middle of June, then with 

 two applications of the ammoniacal carbonate of copper, and 

 which were not in the least disfigured. 



An analysis of these two samples was made at the State 

 Elxperiment Station. In the first, sample No. 1, there was 



