264 



SCIENCE. 



[N. S. Vol. XXIII. No. 581. 



measuring the rise of temperature of the 

 water recorded photographically, and the rate 

 of flow of the water, and time of observation 

 were also automatically recorded. This con- 

 tinuous, self-recording and proved instrument 

 is thought to be a standard pyrheliometer. 



In the general discussion that followed, at- 

 tention was called to Professor 0. A. Young's 

 observations with a faulty Pouillet pyrheli- 

 ometer in 1872 at Sherman, "Wyo., and by Mr. 

 Eosa to the analogy of the new instrument 

 to his great calorimeter used in physiological 

 experiments at Middletown. 



Mr. L. J. Briggs then described the ' Cen- 

 trifugal Methods of Soil Investigation ' used 

 at the Department of Agriculture, where some 

 3,000 soil analyses are made per annum. 

 Since a force 2,000 times that of gravity is 

 available it is easy to produce stratification in 

 a five-gram sample of soil and then to de- 

 termine the percentages of sand, silt or clay. 

 Further, the water-content of such soils that 

 remains after exposure to a drying force is 

 found as a function of the force and of the 

 percentages of the soil-constituents. Lantern 

 slides illustrated the apparatus and many re- 

 sults. The velocities used run up to 5,000 

 turns per minute; but a steam turbine has 

 been ordered capable of reaching 30,000 turns. 

 Charles K. Wead, 



Secretary. 



THE BIOLOGICAL SOCIETY OF WASHINGTON. 



The 407th regular meeting of the Biological 

 Society of Washington was held December 8, 

 1905, with the president in the chair and 

 thirty-seven persons present. 



This meeting was in celebration of the 

 twenty-fifth anniversary of the foundation of 

 the society, at which the following papers 

 were read: 

 The Potomac-Side Naturalists' Cluh (here 



given in full) : Professor J. W. Chickering. 



In the FlorEe Columbians Prodromus, com- 

 piled by John A. Brereton, M.D., U. S. A., 

 and ' printed in Washington by Jonathan 

 Elliot, and sold at his store on Pennsylvania 

 Avenue ' in 1830, we find it stated in the pref- 

 ace that 



During the spring of the year 1825, after the 

 dissolution of the late Washington Botanical So- 

 ciety, a few gentlemen of this city, devoted to 

 the science of botany, formed an association, with 

 an earaest determination to explore and to in- 

 vestigate, de novo, the indigenous plants growing 

 in the District of CJolumbia. 



This association under the name of ' The Bo- 

 tanic Club,' consisted of Wm. Mechlin, Alex. 

 McWilliams, M.D., Wm. Kich, the compiler, and 

 during the following year, of James W. Robbins, 

 M.D. 



One result of this association was the pub- 

 lication of this ' Prodromus ' containing 1,922 

 specie's. How long ' The Botanic Club ' lasted, 

 we know not. 



In the ' Records,' which have come into my 

 possession, of the Potomac-Side Naturalists' 

 Club, it is set down that in January 29, 1858, 



With the view of forming a scientific club, 

 especially devoted to Natural History, the follow- 

 ing gentlemen met at Mr. Simpson's' house at 

 seven o'clock in the evening: Mr. T. R. Peale, Dr. 

 E. Freman, Prof. G. O. Schaefer, Dr. C. Girard, 

 Dr. F. V. Hayden, Dr. T. G. Cooper, Mr. Robert 

 Kennieott, Mr. W. Stimpson, with Professor Tur- 

 ner and' Mr. W. R. Smith recognized as present 

 in spirit and thus original members. 



They adopted the name of Potomac-Side 

 Naturalists' Club, with the provisions that: 



The meetings shall be held every Monday eve- 

 ning. The members shall severally entertain the 

 club in rotation in alphabetical order. 



The member whose name follows the enter- 

 tainers, shall at each meeting, deliver a lecture or 

 read a paper upon some subject in natural science 

 chosen by himself. 



This meeting adjourned at 2 :30 a.m. 



In this catalogue are found the names of 

 about fifty members, only a very few of whom 

 still survive. 



Two very interesting record books still re- 

 main, with accounts of each meeting, mem- 

 bers present, papers read, and discussions fol- 

 lowing. 



In the various departments of investigation 

 and discussion, geology most frequently oc- 

 cupied the evening, with zoology, botany and 

 general science, following closely after, in fre- 

 quency of notice. 



The average attendance was ten to fifteen. 



At one meeting we find a note. 



