866 



SCIENCE. 



[N. S. Vol. XVI. No. 413. 



of signals could be hastened or delayed with- 

 out altei-ation of the interval. The interval 

 itself could be altered at pleasure while the 

 apparatus was in operation. Though the de- 

 sign was illustrated primarily as a mechanical 

 device which might find many applications, 

 it was pointed out that it was immediately 

 applicable to Mr. Langley's method of prevent- 

 ing personal equation in transit observations. 

 Mr. W. J. Spillman, of the U. S. Department 

 of Agriculture, read a paper on ' The Theory 

 of Combinations Applied to Mendel's Law.' 

 He first stated briefly the law, which expresses 

 the probable character of hybrids and their 

 progeny, and the theory which Mendel and 

 others had proposed to explain the facts in the 

 ease, illustrating the theory for monohybrids 

 and dihybrids, and giving general formulffi 

 he had deduced for finding the number of 

 types that may be expected in the progeny of 

 any hybrid, and the relative proportion of 

 each type in any generation of any hybrid. 

 He then showed what departures from the 

 law may be caused by chance distribution of 

 parent characters in the progeny. Taking the 

 hypothetical case in which each hybrid pro- 

 duces ten ovules, he showed that " the chance 

 that five shall possess a character of one parent 

 and five the corresponding opposite character 

 of the other parent is 25 per cent. In other 

 words, when there are ten ovules on each 

 plant, in 25 per cent, of the cases we may 

 expect to find the pair of characters distrib- 

 uted amongst the ovules exactly as called for 

 by theory. In .1 per cent, of the cases all the 

 ovules will possess the character of one parent, 

 and all will possess the character of the other 

 in a like number of eases. If each plant has 

 100 ovules, the pair of parent characters will, 

 be equally distributed in only 8 per cent, of 

 the cases." The chance than any particular 

 distribution of a pair of characters amongst 

 the ovules shall occur was shown to be 



2"r ! (n — »■)!' 



pollen which shall fertilize these ovules shall 

 be such as to give any particular combination 

 of the possible types in the progeny. Lantern 

 illustrations showed the results obtained by 

 crossing varieties of wheat, and graphically 

 some of the results of mathematical analysis. 

 Mr. Marcus Baker then discussed the 

 question ' Can the Equations 



U + 2/^ = 



:} 



where n = the number of ovules per plant, and 

 r^the number of ovules on any plant that 

 possesses the same parent character. He also 

 gave a formula to show the chance that the 



be Solved by Quadratics ? ' He pointed out 

 some relations of this problem to the theory 

 of equations, showed that the general method 

 of solving equations of the second and third 

 degrees consists in reducing their degree or 

 in transforming them to some typical form 

 which is solvable, and gave the criteria by 

 which the few solvable types of equations of 

 the fourth degree may be recognized. Ac- 

 cording to these criteria the given equations 

 cannot be solved by direct methods. 



At the 556th meeting of the Society, held 

 October 25, Professor S. W. Stratton, director 

 of the . National Bureau of Standards, spoke 

 on ' The Present Status of the Metric System 

 in the United States and Great Britain,' de- 

 tailing the various attempts to obtain permis- 

 sive legislation, and some of the numerous 

 associations and societies that had forwarded 

 memorials to Congress. 



Professor E. B. Rosa, also of the bureau, 

 then by invitation, with the aid of lantern 

 views, described the ' Plans for the Buildings 

 of the National Bureau of Standards.' One 

 building is to contain all the machinery, while 

 another is to be as free as possible from jar; 

 every modern convenience is to be provided 

 in the various rooms, the temperatures of 

 which will be regulated by thermostats con- 

 trolling the supply of dust-free warm or 

 cooled air. 



Chahles K. Wead, 



Secretary. 



NEW YORK ACADEMY OF SCIENCES, SECTION OP 

 ASTRONOMY, PHYSICS AND CHEMISTRY. 



At the meeting of October 6, 1902, the pro- 

 gram of the evening was made up of informal 



