i Lie. REPORTS ON THE STATE OF SCIENCE.—1912. 
Taste III.—Results at Washington with N.P.L. Non-septum Voltameter. 
Calculated E.M.F. of , 
Date, 1910 Weston Normal Cell seiner from Mean. 
at 20° C, x10-5 
April 15 1-:01831 +2 
” 15 28 =i | 
eee 31 +2 
Pee) 28 —l 
» 30 31 +2 
May 2 27 —2 
» 5 28 ad 
Pan 4 25 —4 
| 
Mean=1-01829. 
satisfactory, is not therefore a true indication of the reproducibility of 
the silver voltameter. To give an idea of this reproducibility the results 
obtained at Washington with a non-septum form of voltameter, designed 
at the National Physical Laboratory, are given in Table III. The results 
of one experiment only have been omitted and in that the current was 
unusually unsteady. 
Table IY. gives the results of measurements on a number of Weston 
normal cells. The values given are the differences in microvolts between 
the u.m.F.’s of the cells and the reference standards of the various 
laboratories. 
TaBLe 1V.—Differences in Microvolts. 
B.S. N.P.L. | PTR. | NPL. | 3.08. NPD. Se 
Stand. June and Aug. Sept. and Oct. Oct. |Nov. and| Jan. 
Cell No. | July i911 | 1911 | Oct.1911 | 1911 1911 |Dec. 1911) 1912 
262 —6 | — — 70 — | -80 | -6 | — 
267 41. | — 0 See a og 
| 268 37 ~~ — 15 = ae ai a 
51 Se att) = Be ee = 
32 a —115 2s —130 == a 
301 —2 As ys ns 5 a —40 
304 19 23 0 = 0 bes 7 
309 —36 ao, — 45 _ = 20 = —56 
310 0 aA 95 soo — 10 = —44 
Al is —12 Sap; = = 10 — =22 
43 2 3 — 30 — 5 = 0 
44 0 = Tee —7 = = = it 
19 37 a — 45 —30 = = —28 
22 eel ae iG —29 ae a —30 
238 —2 — 20 52 — = —10 
350 —-24 | — — 20 1 _ — —24 
[re Bag sa Agy a cae — 45 —30 -— — —30 
iss citth ss Aw oS — = 30 a 34 
142 — |= _ = 30 a 33 
a3 = == a — —— — 6 — 56 
ig ye = = = = =16 |"Sa6 
17 ~- ee = Ties 
The Committee feel that these results are sufficient to show that the 
primary objects for which they were appointed have been achieved, and 
