40 REPORTS ON THE STATE OF SCIENCE. 
TaBLE II.—Giving the Results of Comparisons made November 1908 to 
March 1909. Values at 20° C. 
| Resistance as determined at | Sstelae Ipc 00 
No. of Coil | } 
P.T.R. N.P.L. | 
NBS: |) N- PIs (Nov.1908 |(Feb.-Mar. N.P.L.- N.P.L- | 
(Sep. 1908) (Nov. 1908) 7... 1909) | 1909) N.B.S. PTR. | 
| elead See 
1. (8.5.1102a) . | 0-99999,; 1:00002,; — = 2°6 t= | 
2. (B.5.1102B) . | 0°99999,| 1:00002, — — 25e hiwiee. | 
3. (B.S. 1102c) . | 1:00000,| 1-00001, — — 16 — | 
4. (B.S.1102pD) . | 0:99999,| 1°00U01, | 0°99995, | 1:00001, 2-1 | 16 
11. (B.>. 5315c)  .  0°99999,| 1:00001,/ 1:0000u, | 1-00002, 2:9) ese? 
12. (B.S 5315D) . | 0°99998,; 1:00000,| 1:99998, | 1:00001, | 2°6 | 18 | 
1. (B.S. 3946E) . | 99°991, | 99°994, -— ob ope eae) Meant | 
2, (B.S. 3946F) . |99987, | 99°990, _ =) fh hyo a 
| | a a eee 
| Mean.| 25 | 1% | 
The unit coils Nos. 1 and 2 were adjusted at Washington on 
September 23, 1908, so as to give values more nearly equal to the 
nominal, The changes made were +0°00019. ohm and +0°00024 ohm 
respectively. 
Analysis of all the data relating to the comparisons indicates that the 
coil No. 11 (Table II.) changed by about 0°00001 ohm during trans- 
portation from Teddington to Charlottenburg. 
No, 12 is a comparatively new coil, having been sealed in January 
1908. 
At the Bureau of Standards (Washington) wire coils were employed 
as standards in all the comparisons. 
The values given by the N.P.L. in Table I. are in terms of the 
N.P.L. mercury standards of resistance, which were set up in Novem- 
ber to December 1907. The N.P.L. values in Table II. are in terms of 
the mercury standards of resistance which were erected in February 
1909. 
With respect to the values given by the Reichsanstalt, in Table I., 
Dr. Lindeck states, ‘The last complete series of measurements on 
the standards of the Reichsanstalt was carried out at the end of January 
and the beginning of February. The values given in the Table (I.) are 
based upon this series.’ 
In Table II. the P.T.R. values depend upon the values assigned 
to a wire standard of the Reichsanstalt which had been kept for about a 
year in an atmosphere of constant humidity, and frequently compared 
with other standards of resistance. 
In conclusion the Committee recommend that they be reappointed 
for the purpose of continuing their researches on the standards and 
carrying out the republications of the Reports if sanctioned by the 
General Committee, and that Lord Rayleigh be Chairman and Dr. R. T. 
Glazebrook Secretary. 
