904 



SCIENCE 



[N. S. Vol. XXXIII. No. S58 



made commercially successful. In the field plant- 

 ings bushes grown from the seed hare been chiefly 

 used, but the propagation of superior varieties by 

 layering and by cuttings is now in progress, one 

 of the varieties having berries over half an inch 

 in diameter. 



The acid lands on which the blueberry grows 

 best are commonly regarded as of little value 

 agriculturally. Blueberry culture offers a special 

 means for the utilization of such lands. 



The blueberry is not alone in its ability to 

 thrive in an acid soil. Experiments with various 

 other plants indicate similar characteristics. For 

 example, the wild trailing arbutus, which has been 

 regarded as exceedingly difficult of cultivation, 

 grows luxuriantly when potted in the acid peaty 

 soil found so successful for the blueberry. Excep- 

 tionally beautiful flowering plants have been 

 grown from the seed in less than two years. There 

 is no reason why trailing arbutus can not be added 

 to the choice potted plants of the florists' trade. 



It is impossible to foretell to what extent other 

 useful plants than the blueberry will be found to 

 be adapted to acid soils. The cranberry is clearly 

 an acid soil plant. Dr. H. J. Wheeler, of the 

 Ehode Island Agricultural Experiment Station, 

 has shown that the strawberry, the potato, rye, 

 lupin and buckwheat grow as well or a little 

 better without the use of lime. In other words, 

 they are acid soil plants. 



It is not altogether a dream to foresee the 

 development of a special acid land agriculture, in 

 which the rotations shall include only such crops 

 as prefer an acid soil or are indifferent to acidity. 

 The New Cosmogony. 



The Extension of the Solar System beyond Nep- 

 tune and the Connection Existing between 

 Planets and Comets. 



The Secular Effects of the Increase of the Sun's 

 Mass upon the Mean Motions, Major Axes and 

 Eccentricities of the Orbits of the Planets: 

 T. J. J. See, Mare Island, Cal. 



Extension of Our Knowledge of the Atmosphere: 

 A. L. Eotch, Harvard University. (Introduced 

 by Professor W. M. Davis.) 



One Hundred and Seventy-five Parabolic Orbits 

 and other Sesults deduced from over 6,S00 

 Meteors: C. P. Olh-iee, of Charlottesville, Va. 

 (Introduced by Professor Cleveland Abbe.) 



The Solar Constant of Sadiation: C. D. Abbott, 

 Smithsonian Institution. (Introduced by Dr. 

 C. D. Walcott.) 

 If we had no eyes we should stiU know of the 



sun by the feeling of warmth. The most exact 

 measurements of the intensity of the rays of the 

 sun, whether they be visible to the eye or affect 

 the photographic plate or not, are made by an 

 electrical thermometer called the bolometer. This 

 instrument is so sensitive that a millionth part of 

 a degree change of temperature is recorded by it. 

 For seven years the bolometer has been used by 

 the staff of the Astrophysical Observatory of the 

 Smithsonian Institution to measure the solar con- 

 stant of radiation. This constant represents the 

 number of degrees (centigrade) which one gram 

 of water would rise in temperature if all the 

 solar radiation which could pass through an open- 

 ing one centimeter square outside the earth's 

 atmosphere, but at the earth 's mean distance from 

 the sun, could be used for one minute to heat the 

 water. As all life and almost all forces on the 

 earth depend on the supply of solar rays, the 

 solar constant of radiation is at least equal in 

 importance to the knowledge of the sun 's distance. 



The value of the solar constant was unknown 

 within wide limits only five years ago. It is now 

 believed to be within 1 per cent, of 1.93 calories 

 per square centimeter per minute. Measurements 

 made at Washington (sea level), Mt. Wilson (one 

 mUe elevation and Mt. Whitney (nearly three 

 miles elevation) agree in fixing this conclusion. 



Nearly 500 determinations have been made. 

 They indicate that the value is not really a ' ' con- 

 stant," but fluctuates about the mean just given 

 within a range of 8 per cent. This conclusion 

 means that the sun is a variable star. It is hoped 

 soon to verify it completely, and it may prove for 

 meteorology hardly less important than the deter- 

 mination of the mean value of the solar constant 

 itself. 



Some Curiosities in the Motions of Asteroids: 



Erxest W. Brown, professor of mathematics, 



Tale University. 

 Spectroscopic Proof of the Sepulsion by the Sun 



of Gaseous Molecules in the Tail of Ealley's 



Comet: Pekcival Lowell, director of Lowell 



Observatory, Flagstaff, Ariz. 

 Self-luminous Night Maze: Edwakd E. Baexarb, 



astronomer, Yerkes Observatory, Williams Bay, 



Wis. 

 Some Peculiarities in the Motions of the Stars: 



W. W. Campbell, director of Lick Observatory, 



Mt. Hamilton, Cal. 

 Taking a Census of the Chemical Industries: 



Chaeles E. Mdnroe, professor of chemistry, 



George Washington University, Washington, 



