NO. I PERIODS RELATED TO 273 MONTHS—ABBOT 7 
= « - +40 #60 5 
35) eee dee 120 140——«160 rm) 
1gsQ 
gil +12 +23 -20-3 kee Feet + 60, , 605-4) -52 -95 -93 -45 478 +48 -11 -FO 442470 -205 76 
413 -33 -33-36-34% -77 -52 +1 3 -§6 -/0 1-17-98 -61-103 -38 469496 -12 -44 445 265-324 73 
“30 <4 -26-/8 -26 -58 ~/0l +21 weet Tt& -76 -56 -30 +80 +)50-|7 -36 +4F265-94 86 
Apr 34 23 33 452-18 O -S2415 469 +7 492 F Rh - (5 489 4135-21 -F 450462 4388 126 
tH ¢14 20 629-9 444 © 6-19 £45 +31 ¥29+ RQ2 593 4515-28 +5 453460 +522 150 
12 426 -32 43243 +61 4/9 “Hl - IF 426425) 445 614 -39 t21 46497 4100-26 430 455467 44%. 144 
Jur +13 +14 -26 -18 4/8 4/08 +91 -18 -/4 +30 429 “p3-21 +49 457 57+ GH2-141 
-30 416 +43 -38 +84 + 7 4111-29 -47 <1! +1 75-36 +5% 458454 4649 [41 
= 9-39 +49 -36 -9 -30 +92-17 -20-3! 4244 © 428 +)2 + 466-32 +397 4604524705 [YI 
Oct 415 -4 446 -16 +3 -53-37-/6 +2-86-2 ee 454-32 452 462 +46 +263 [20 
-30 -2 443 452 HG 44 £19457 +/3 - FY ~46 334 P44 3) YS 463 F444452-1I0 
6% +4 =—4 ¢#9 427499 $60 491 499 451 +7 -50-6244%2 449 244-30 +39 +64¢4+424674 163 
Jan t10 -2% -/3 F32-14 4108 till +15 469 431-56 fo +3 $5224 436 463 4394683 173 
HID +14 -20 - 18 -34 47 432-14 445 +26 —6oj-/ 5 +17 -28 #21 4624964307 14° 
WB 426 -3% -38 -26 -30-17 - Yt -I5 4307/0 49 -25 413 4664324)25:130 
Apr -39-33 -26-36-16 53-1) -)8 ~48 465 49 =. =) <2) HO +60 +30 -7F5/N7 
+H +14 =13 -18 484 ~77 $2,-29 “33 42% tye bo HHe -16 -19 +10 437 42% 4 32 (28 
+4 426 -20 452 -/4 -58-l04-/5 -14 ee 3-22-15 410 +58425-IF% 21 
ul 412-39 -32429-34 = O-52-[6 -4H7 - z - -30-(0 4/0 +574+Z2-176 154 
1-52 -3 +14 =X & -41-6 4/5 +52420+26 JS2 
7 sol =27 38 “S00 *20 4464/9 -17¢ 132. 
WER +25S -24-S4-36 -&7 -53 +2 422 4364/5 - 89 96 
= -2|-53 +49 ~29-99-38 -99 -6L47 4/0 439 +/0- 120 62 
eS) F FCF +31 -4G-42 -4i -45°-93 -40 -7g -65 41% =i 42046 — 422 4Y 
+4 4216 ~/3 452-14 eSRR-IT dl 445 426 -SOj- 62-86 -61 -76 - 46-94 -§9 4/7 -J0, +12 +7 ~ 588 50 
$12,733 -20 417-3 OXI! -I6 -[F 430 ~-56]-H 1-142 -16 -93 -49 424 273420) -UIS +71 44 ~639 53 
g/L -33 °52432-26 aw - <8 465 -60l- 17-90 -f0-103 -50 430 -77423 -I32+2 O- 617 67 
Apr +(3 -33 -26 -16 -1€ +6 4—qe -15 + PeeslO]+ 7 -52 -37 -5%-S1- 12 -78 t56 -BO ~6 -3 - 45198 
30 -H ~13 -3€ -9 4/08 -32 PONE SE +1 FPmo —& -22- 4 52. -Su TS AUS M4 “IT “5-215 [08 
FH 92-20-36 43 +7 415 457 451 ~3 Somes 46 4 49 -F0 -42-71 446 30-27 -8 + 48 105 
Jul +H 41H 432-13 416 -30 49) 440469 -({ 429|+CP RE RI2 421 -50 -30-°67 447 —S 231-16 4152 II 
HI2Z4EL] -264$2 45K -F3 +) 92( $y5-3) 425850 423 tees 4S -20-60447 $5 -39 IF 4320 133 
419 -H 443429 -9 -77 432418 -IS-86 +29h63 FTES +88 -36 +6 -5D4i7 $30 -45°-1% +507 LI 
Oct -30-2 +49 432,43 -SB -17 +1F -48 -59 t4[ R50 tPA PPR ADL -30 454 HOWE THI 246 -224167 127 
-G +14 +43 “IF flo 0 =I) (4 -33 £7 ed ¥e HZ HIF +28 -ZOp yy +52 —H7 -25 +239 134 
jg7e +13 426444 “36 984 F44 -$2.-4) -14 231 - 25-1 +105 RAF £43.-3 278-2144) 457 a0 -27+392 127 
Jan -30 -33 -13 -36 -/f ¢57-52-1§ -H7 +26 ~4 t18 41S +69 -13437 +452 -S54-25 Hus 125 
#4 -33-20 -)8 -34-77 -& ~29-20 430 -So AZ 430780 O+K 24S FO -BM. 1 132 
FID 94-32 452,-26-58 HIS +1542 OS -56 4748Y #20421 +39 ~57 -30 4100 147 
Apr 41 22-26 429-18 6 -I1 +16 4/3 428-60 +65493 295417 430-02 ~32 4 (29 137 
213 +14 -13 432733 t44¢-S2457 +51 O- 10 BB0+99 +964!) FU “GS-35 +445 146 
-30 +16720 -/8 +84 +6) -J00 +40 +69 ~ 11419 FIOO+) +15048 419768 -379 2434139 
Jul +4 +)y -32 -38-/0+)09 -52 ¢214us -3) +42) tS +92497 H354+3 410 -70 -424277 (23 
tH 436-26 -36-349 +7 -6 -1Y -1S ~ 36437. PrS6 29 $55 480479 HIF -3 +10 -7) -4S =34 Jo 
FID 933 44S -18/-26 -30 +1F -Hl - UH ~F4.% G0 -/42 -2941/9 463480 F/0F-F +/0 -7) -¥7 ~f36 10 
Oct £13 -4 449 452718 -53 49) -5% -33 +7 42 P~ FO ~4S5-27 496444 FFZ-IZ 410 -70 -SOeI04 109 
$30 2443 629 ~~ YH $110 -29--19 431 TYEE -52 -61-59 430425 476 -12 415 —68-51 486 9% 
TF - F ~-44H9 £32 +3 HHO 43L-IF -UT 4B FIMT TSO — %-76-99 +742) 466-17 +20 -56-S2—14 g 
Jan #12 -2-J3 -]8 +16 $61 -t7 -16 -20 +f 4S +6 ~ 80-93 -/3 +4 454 -21_ 422 -59 -53-15¥ 73 
+13 +14-24 -3 +14 9108-11 457 + 2 -() 435 -5F-%6 - 20-66 4N¢-25 +10 -56 Sy -164 757: 
-30 426°92 -36-34 +7 >& =29 $18 -39 93 -30-84 434-18 -/4 -$0-55 -483 52 
Apr 44 -33-26 - (8 “20% -/Op +24 451 +2 4/94 -22-103 -35-FO 425-31 -T0 -yo-56 -Gos 5? 
+4 +14 713 +52°/8 - $15 469 Ul -GOj-53 46 44 - 56435 -83 417 -32°//5 -4YO-57-S00 SE 
$12426-20 427 -F9 -\746 ld 445 3! -10)-92 435 4/2 -1) » 40°76 FF -32-13% -3F-SB-4TS GI 
Jurt 4/3 ~ 33-32 25I2 43 “sae Hl -/5 -@6 +19 |-62428 4254+9 -46-S6 -| -32 -80 -30-S7 -yes ST 
30-4 -26 -“{(@416 O BP we Hig 48-4) 4/9 2 421 -U¢ -91 -10 -31 = ARES fod 
-2 443-39 Tey Hud ain -F 4 -lBN SY 449 478 -50-87 +22.-39 °30 -17 ~SS+l0r 
Oct 156 4449 36 hd +61 352 LES zt ete 46% 469-51 -93 ~30-29 -§ -12-SS 416 LO 
FH -2 443-18 43 41-17 -K-47 416 FR fOS+7T) +72-52. -98 41.28 +S = 5 -SS +1859 
RID FIG 449 HAH 47 415 459-32 430 HHL EINES FQ 157 “50-44-50 ~25 430 +2 -50 4325 [| 
7-30 $14 449-18 +16 ~# 
Jan 
= sg 
- 
Fic. 1.—Facsimile of computation of St. Louis precipitation, 1875-1879, compared 
with the observed precipitation as percentage of normal. Data from monthly mean 
precipitation smoothed by 5-month running means. Dotted curve from summation of 
22 regular periodicities, determined as averages over the 84-year epoch, 1854-1939. Full 
curve, the event. 
displaced one or more months. These displacements seemed generally 
to follow either great volcanic eruptions, such as Krakatoa, Colima, 
and Katmai, or great bombing periods, as in the war years 1916-1918 
and 1940-1945, and recent tests of atomic bombs. 
The results, though subject to such blemishes, seem to offer a 
useful means of mapping countries for decades in advance to exhibit 
probable precipitation in percentages of the normal. Suppose 50 
