10 REPORTS ON THE STATE OF SCIENCE.—1917, 
TABLE I. 
Observed Corrections to P and S from Galitzin and Wiechert Machines in 
1913-1914. 
P 8 
A G No W No. W-G G No. WwW No. W-G 
ie 8. 8. S| 3. s. s. 
8 0:0 7 +44 43 +44 , — 17 3 + 88 25 +10°5 
13 + 06 8 +32 22 +26 | —12°9 7 —t11 14 +118 
18 — 03 18 +03 34 +06 > —06 16 +41 28 4+ 4:7 
23 — 05 20 —0O3 41 +02 — 67 21 — 14 29 + 53 
28 — 6:2 26 —42 39 +2°0 —109 23 — 77 34 + 3:2 
33 — 5:3 20 —10 26 +4:3 —240 10 —10°'7 14 +13°3 
. 38 — 66 22 —33 33 +3°3 —18°8 20 —135 26 + 53 
43 — 2:0 13 —02 26 +1°8 —125 12 —144 18 — 19 
48 — 3:1 27 +23 25 +59 | —102 24 — 3:8 21 + 6-4 
53 — 1:9 24 436 14 +55 | — 21 17 — 30 10 — 0:9 
58 + 18 48 +88 17 +70 | +28 37 + 2:2 9 — 06 
lseGop ea Lb 34 +54 14 +3°9 | — 40 34 + 68 11] 10°8 
68 -|- 2-2 Bi] PS 2t2 EGE? 0-0) == 39 46 + 213 = WOE2 
73 — 10 64 +47 38 +57 | — 65 51 4+ 82 36 + 8-7 
78 — 17 51 —l1l 56 +06 | — 83 51 —11 53 + 7:2 
83 — 16 37 —14 101 +02 —118 36 —T71 99 +4 4:7 
88 + 231 36 +1:°0 52 —I1'1 —167 36 —141 55 -)2°6 
93 — 57 19 —1'8 34 +323°9 — — — _ —- 
98 — 7'3 Il —07 35 +66 — — — — — | 
103 —12'7 24 —32 14 +95 echoed Tanta teeeee 
De ee oer n= eee Ser hes te. | 
| 113 —156 2 —- -—- —- — = 
118 — 64 wf —_- —- — — —_— -— _ — 
123 — 12 6 - —- — — — — — — 
spondingly larger corrections for 8. These large corrections are not 
confirmed by the present investigation, which shows quite small corrections 
in this neighbourhood. The attempted explanation of the phenomenon 
PX on these lines must therefore be given up. There is no doubt about 
the reality of the phenomenon, or of that designated Y ; but the explana- 
tions of both must be sought on other lines. 
Turning to the bottom of the table we see that records of P fail rapidly 
after A=110° even for G machines, and entirely for W machines. After 
A=105° there are two records only by W machines at all near the tables : 
—7s. at A=106°, and +10s. at A=115°. Other records are (in seconds 
of time) : -- 
A 
° ° 
106-110 | —91 —61 +62 +148 +156 +242 +268 
111-115 —110 +36 +147 +154 +205 +214 +271 
116-120 +204 +269 +328 +359 +611 
121-125 +180 +192 +194 +196 +197 +197 +198-+ 208+ 209 
+209+2114 218+2744-277+283+331 +340+ 621 
At distances 4=121°-125° it is clear that the records of P relate 
to what has been called PX, following P by about 200 seconds, but it is 
not altogether clear whether the transition is gradual or abrupt. Several 
investigators have treated PX as the true P; have remarked on the 
