544 



SCIENCE. 



A paper on the " Electrical Resistance and the Coeffi- 

 cient of Expansion of Incandescent Platinum," by E. L. 

 Nichols, Ph.D., was read at the Cincinnati Meeting of the 

 American Association for the Advancement of Science, 

 August, 1 88 1, fully reported in Amer. Jour. Science, 

 November. In his discussion of the subject, the author 

 after showing the discrepancies in the formula; of resist- 

 ances as obtained by Siemens, Benoit, Matthiesen, 

 and other physicists, draws the following conclusions : — 



ist. The formula; in question are based for the most 

 part upon unwarrantable suppositions, such as the con- 

 stancy of the specific heat of copper and of platinum ; 

 the constancy of the coefficient of expansion of the latter 

 metal, and upon the accuracy of certain very doubtful 

 values for the boiling points of zinc, cadmium, etc. 



2d. That, aside from the inaccuracy of those data, the 

 varying resistance of different specimens of platinum 

 renders any formula for the calculation of temperature of 

 that metal from its electric resistance applicable only to 

 the identical wire for which the law of change of resist- 

 ance with the temperature has been determined. 



3d. That from the data at command we are not in posi- 

 tion to calculate the temperature of an incandescent 

 platinum wire from its change of resistance, nor from its 

 length, nor indeed in any other manner, further than to 

 express the temperature in terms of the length or the re- 

 sistance of the wire. 



4th. That, owing to the great variations shown by dif- 

 ferent specimens of platinum as regards its resistance, the 

 determination of the expansion of the wire is to be pre- 

 ferred, whenever practicable, to the measurement of its 

 conductivity. 



CORRESPONDENCE. 



The Editor does not hold himself responsible for opinions expressed 

 by his correspondents. No notice is taken of anonymous communi- 

 cations.] 



To the Editor of " Science." 



Dr. Rogers seems again to misunderstand. It was not 

 his quotation from Faraday that, was objected to, but the 

 use apparently made of it to support his strange " ques- 

 tioning of the dogma that ' gravity acts in versely as the 

 square of the distance,' on the ground that if that force 

 is weakened by the earth's being removed to aphelion, 

 it could not again bring back the body to perihelion." 

 Any attempt to sustain that position by the authority of 

 Faraday must certainly be a failure. Your correspondent . 

 seems not to distinguish between the definition of the 

 force of gravitation, to which Faraday pertinently ob- 

 jected, and the law of gravitating action to which I par- 

 ticularly referred, and concerning which Faraday says, 

 in the sentence immediately preceding that quoted by 

 your correspondent, " It will not be imagined for a mo- 

 ment that I am opposed to what may be called the law of 

 gravitating action, that is, the law by which all the known 

 effects of gravity are governed:" — the very "dogma" 

 your correspondent assumed to question ! 



Geo. B. Merriman. 



Novembet 2, 1881. 



METEOROLOGICAL REPORT FOR NEW YORK CITY FOR THE WEEK ENDING NOV. 5, 1881. 



Latitude 40 45' 58" N.; Longitude 73° 57' 58° W.; height of instruments above the ground, 53 feet ; above the sea, 97 



feet ; by self-recording instruments. 



BAROMETER. THERMOMETERS. 



OCTOBER 



AND 



NOVEMBER. 



MEAN FOR 

 THE DAY. 



MAXIMUM. 



MINIMUM. 



MEAN. 



MAXIMUM. 



MINIMUM. 



maxi'm 



Reduced 

 to 



Freezing. 



Reduced 

 to 



Freezing. 



Time. 



Reduced 

 to 



Freezing. 



Time. 



Dry 

 Bulb. 



Wet 

 Bulb. 



Dry 

 Bulb. 



Time. 



Wet 

 Bulb. 



Time. 



Drj- 

 Bulb. 



62 

 62 

 55 

 53 

 47 

 3» 

 36 



Time. 



Wet 

 Bulb. 



Time. 



In Sun. 



Sunday, 30.. 

 Monday, 31.. 

 Tuesday. i-- 

 Wednesday, 2.. 

 Thursday, 3.. 

 Fiiday, 4-- 

 Saturday, 5-. 



29.893 

 29.750 

 29.846 

 29.949 

 29.591 

 29.586 

 29.990 



29.910 

 29.826 

 29.918 

 29.992 

 29.798 

 29.850 

 30.062 



a. m. 



a. m. 

 12 p. m. 



9 a. m. 



a. m. 

 12 p. m. 



9 a. m. 



29.826 

 29.702 

 29.750 

 29.798 

 29.446 

 29.446 

 29.850 



12 p. m. 



3 P- m. 



a. m. 

 12 p. m. 

 12 p. m. 



a. m. 



a. m. 



66.7 

 67.0 

 58.3 

 55-6 

 56.6 

 41.0 

 48.3 



64.0 

 64.7 

 56.6 



55- 3 



56- 3 

 39.0 

 45-6 



70 

 69 

 62 

 57 

 61 

 47 

 56 



12 m. 

 2 p. m. 



a. m, 



1 p. m. 

 11 a. m. 



a. m. 

 4 P- m - 



65 

 66 

 62 

 57 

 60 

 47 

 52 



12 m. 



2 p. m. 



a. m. 



9 p. m. 

 11 a. m. 



a. m. 



4 p. m. 



a. m. 

 12 p. m. 

 12 p. m. 



7 a. in. 

 12 p. m. 

 12 p. m. 



5 a. m. 



61 

 62 

 54 

 53 

 47 

 37 

 36 



a. m. 

 12 p. m. 

 12 p. m. 



7 a. m. 

 12 p. m. 

 12 p. m. 



5 a. m. 



125. 



74- 



64. 



66. 



7i- 

 103. 

 104. 



Dry. Wet. 



Mean for the week 29.800 inches. Mean for the week 56.2 degrees -54.5 degrees. 



Maximum for the week at 9 a. m., Nov. 5th 30.062 " Maximum for the week. at 12 m. 30th 70. at 2pm3ist, 66. 



Minimum " at 12 p. m., Nov. 3d 29.446 " Minimum " 11 5 am. 5th 36. " at 5 am 5th, 36. " 



Range 616 M Range " " 34. " 30. " 



WIND. 



HYGROMETER. 



CLOUDS. 



RAIN AND SNOW 



| OZONE. 



OCTOBER 



DIRECTION. 



VELOCITY 

 IN M1LBS. 



FORCE IN 

 LBS. PER 

 SQR. FEET. 



FORCE OF VAPOR. 



RELATIVE 

 HUMIDITY. 



CLEAR, 

 OVERCAST. 





 10 



DEPTH OF RAIN AND SNOW 

 IN INCHES. 



AND 



NOVEMBER. 



7 a. m. 



2 p. m. 



9 P- m. 



Distance 

 for the 

 Day. 



. 

 X 



9 



s 



Time. 



B 



(d 

 r» 



B 

 6* 

 n 



e 



d 



6 



B 

 d 



e 



d 



0* 



B 

 « 



B 

 d 



B 



ui 'd 6 



Tim* Time 



of of 

 Begin- End- 

 ning. 1 ing. 



Dura- 

 tion, 

 h. m. 



1 Amount 

 'of water 





 [O 



Sunday, 30. 



w. n.w. 



s. w. 



s. s. w. 



106 



3 



9.10pm 



• 5" 



.564 



•577 



94 



79 



84 



9 cu. 



8 cu. 



10 



oam 4.30 am 

 4.45pm 12 pm 



4.30 

 7-15 



.09 

 .02 







Monday, 31. 



s. w. 



s. w. 



e. n. e. 



147 



8 



10.15 am 



■577 



•599 



.562 



84 



84 



94 



JO 



10 



i 1 



oam 4.30 am 

 9 am 12 pm 



4.30 

 15.00 



•17 

 •14 







Tuesday, 1. 

 Wednesday, 2. 



n. e. 

 n. n. e. 



n. e. 

 e. n. e. 



n. e. 



e. s. e. 



215 

 150 



sH 

 <K 



7.50 am 

 10.00 am 



.487 

 .403 



.422 



■43° 



■407 



.466 



94 

 100 



87 



93 



87 

 100 



xo 



9 cu. 



9 cu. 

 10 



6 cu. 



oam |8 am 



8.00 



•07 



5 

 



Thursday, 3. 



s. e. 



w. 



n. w. 



104 



651 



9.15pm 



.466 



.487 



.403 



100 



94 



100 



10 



9 cu. 



» i 



3 am 8 am 

 8.30am 12 pm 



5.00 

 3-30 



•<=5 

 .18 



10 



Friday, 4. 

 Saturday, 5. 



w. n.w. 

 w. 



w. n.w. 



s. 



w. 

 V s. w. 



374 



230 



7 



6.40 pm 

 10.30pm 



.248 



.220 



.195 

 .282 



..94 



•335 



100 

 100 



67 

 67 



81 

 80 



8 cu. 

 3cir.cu.s 



9 cu. 

 3 cir. 





 



am r . 30 am 



6.30 



.29 





 



Distance traveled during the week 1,326 miles. I Total amount of water for the week 1. 01 inch. 



Maximum force 22K ' Ds - | Duration of rain 2 days, 6 hours, 15 minutes. 



DANIEL DRAPER, Ph. D. 

 Director Meteorological Observatory of the Department of Public Parks, New York. 



