BPBIL, 1908. MONTELY WEAT- REVIEW. 107 Year. I Winter wheat. I Clover. I Maize. Planted. ................ TABLE I.-hfmthly and annual mean lmperaturea a4 four etatima for their longest periods. ~ Apple treea Blomned. 184-1854 ......... Saline, Mich. Detroit, Mich. 1873-1905 ......... .......... Lansing. Mich. 1887-1903 Adrian, Mich. 187&1903 ......... 1847.. ... 1848.. ... lM9 ..... 1850.. ... 1651 ..... lsj2 ..... 1 8 3 .... 1 W .. I AVoum. Harirrlerl. A%,rlW. September 1 .. ................................ .September92.. July 18. ....... March 25.. .... Septemberli.. July 14 ........ March 15.. .... September 11.. July 12.. ..... March 2% ..... Sel~teniber 3.. July 9 ........ March 11 ...... Seytember1-1.. July E.. ..................... September 2.. Jul'y 8.. ..................... ................... July 17 ........................ I n Table 6 are given the temperatures of the warmest and coldest days of each of the years. I have also underscored the temperatures of the warmest and coldest days in the period of the seven years. These are not the extremes of the temper- atures, but are the true daily means. n h y 18. ....... May 1%. ...... May 15. ....... May 17. ....... Average Gepteluber 10.. July 12. .................... May 14.. ...... I TABLE 'I.-Date ofJr8t fmt aid the meair dit& for the earen-year period d Saliite, Mi&. May 21. May 17. May 12. May 11. May 14. . Coldest daya Mean tem- YCM. Date. 1 perature. 0 1847-48.. ......... December %. 9 1848-49.. ......... January 11.. 2 1849-9-50.. ......... Iwcember25. 7 185051.. ......... January 80.. 5 lR51-52.. ......... January 19.. 6 1852-53 ........... January26.. 2 1S53-54.. ......... January 21.. 1.3 ____~ TABLE &--Date for eneh iJear whris froat ram out of ground or the ground wfl8 free .froin .f m t front lS48 to 1854 at 8aliw. Mich. Warmest days. ~- .. Year. Dah. Meantemu- perature. .. 0 1848 ............. June17 ..... 80 I S 9 .............. July 10 ...... 80.6 1850 .............. July 27 ...... 82 1851 ............. July 16 ...... 7% 6 ............. ...... 80.3 1 1 2 JulyR 1851 ............. June22 ..... 82 1 W .............. August1 .... 83.6 ... . .- .. ..... Tear. 1847. ..................................................... is&?. ..................................................... 1849. ..................................................... 18551.. ..................................................... 1852 ...................................................... 1953. .................................................... 1 W . ...................................................... Average.. ............................................ Station. . .- . Date. Conditions. September 14. ... Very IIQ~VY. epteniber la ... Septeinber 8. ... Blight. September 28.. .. September 16.. .. August 28.. ..... September 16.. .. September 13.. .. I- ' --I Tear. Date. - 1848 ............................................ n i m i l 24 ....... 1849. ............................................ March 14 ....... 1850 .............................................. March 13 ....... 1851 ............................................. February 26. ... 1852 .............................................. nfarch 14 ....... 1853 .............................................. Mnrch 21 ....... 1854 .............................................. March 15 ....... Average.. .................................... Marclr 14 ...... ________ ~ - Conditions. Nearly. Except under fences. In Tables 7 and 8 are shown the dates in the different years of the first frost and when the frost was out of the ground, and in Table 9 a comparison has been made of the average time of the first killing frost and the date of the earliest re- Lansing Mi&. ................................. Detroit. 'Mich. ................................... Adrian Mich. ................................... R.line,kich. .................................... corded frost for the four stations, Lansing, Detroit, Adrian, and Saline. The record as kept by Mr. Pope does not indicate generally the severity of the frost. This undoubtedly accounts for the average in the came of Saline. All the comment that he made concerning the nature of the frost is indicated under conditions " in the tables. TABLE 10.- Variow, f a m activities from IS47 to 1656 for Saline, Mi&. September 16.. ........ October 9 ............. September 17. October 11. ........... September :VI Beptemberl3.. ........ August 28. 5 .....I ................ I ................ I ............... 1 May 10.. .... :.I May 5. May IS ........ May 17. l a y 16. ...... .I May 18. nray 1:s. ....... M ~Y io. Table 10 indicates the dates of various farm activities for the different years. There is a rather remarkable uniformity in the dates of planting corn and the blossoming of the apple trees. Also, as we would expect from an observing scientifio farmer, if the wheat were sown early it was harvested early and not allowed to overripen. I n this connection it may be worth noting that Mr. Pope very carefully followed what he found to be the best scheme for wheat yield, namely, letting the ground remain idle for a year and fallowing it in the summer. In this as well as in crop rotation he was doubtless a pioneer. I desire to acknowledge the assistance rendered me by Prof. A. J. Henry, by his advice and by the data furnished me; by Mr. C. F. Schneider, Section Director of Michigan Stateweather Service, for reports which he sent me. I am also greatly in- debted to Mrs. E. S. Ritchie and to other relatives of Mr. Pope, who have made possible this report. EXCESSIVE PRECIPI!L'ATION AT LOUISVILLE, KY. Many requests have been made for information bearing on the frequency of escessive precipitation at Louisville. In order to meet the demand for these data, the records have been carefully examined, beginning with 1871, and after care- ful verification, the entire record of excessive amounts during the past thirty-six years, from January, 1872, to May, 1908, has been tabulated, and appears in Table 1. Precipitation is considered ercessive, (1) when 2.5 inches fall in twenty-four hours, or (2) when the rate of precipita- tion for any short period is equal to, or exceeds, an inch per hour, provided that the total rainfall amounts to at least five- tenths of an inch. During the thirty-six years conaidered, there have been 80 instances of rainfall belonging to one or the other of these cases. They occurred for the most part during the summer months, as shown by count of cases by months, vie, January 3, February 3, March 3, April 6, May 11, June 12, July 13, August 11, September 3, October 4, November 7, and December 5. The heaviest rainfall in one day was on July 4, 1896, when 5.50 inches were recorded between 4.52 and 8.30 p. m., and 2.70 inches between 5 and 6 p. m., of which 1.05 inches occurred in an interval of ten minutes. Streets were flooded to a depth of 2 to 4 feet, and the sewers oould not carry off the water. Later in the same month, 2Oth-2lstY there was a rainfall of 4.19 inches, being the total of several very heavy showers scattered thru the night and day. Again there was much damage thruout the city. Even heavier rains than this at Louisville fell on this latter date at several places in the interior of the State. At Shelbyville, 30 miles east of Louisville, 7.15 inches fell in twenty-four hours, doing an im- mense amount of damage. By F. S. WALZ. B. S., District Forecaster. Dated Louisville, Ky., May 14, 1908 (See Table 2.) 108 MON!I!EZY WEB- REVIEW. APRIL, 1908 Monthand year. -. - The greatest precipitation in any one month was 16.46 inches, in July, 1875. Other large monthly amounts were 13.01 inches, July, 1896; 12.11, January, 1907; 11.43, January 1876; 10.53, August, 1888; and 10.02, August, 1879. There is nothing to indicate any material change in the frequency of excessive rainfalls from one period to another. Thus, out of 80 cases, 24 occurred in the period 1872-1880, 14 in 1881-1890,18 in 1891-1900, and 21 in 1900-1907. The slight apparent increase in the number in recent years is in some measure due to the introduction of recording gages; the float type of gage was introduced October 1, 1894, and the tipping-bucket type January 1,1898. A count of the cases in the individual years indicates a fair distribution, except that the last three years, 1905-1907, include 19 cases. This appears to be due to better methods of meas- urement during especially heavy periods of rainfall, and not to recurring cycles of excessive rainfall. TABLE l.-EzeeReive rainfalls nt LoprieviU-s, Ky., from January, lS72, to May 12, 1908. 2.50 Inches or niore in 24 hours. j 2.60 inches Excearive or more in ~ I 24 hours. I periods. amounts for short Hr.iii. 1:bO 1:ou 1:oo 1:Oo 1:oo n30 030 020 0::30 n:15 O:l5 , . . . . . -- . . . . . . 3 19 4 21 10 :3 25-26 9 15 18 19 . I July, 1877.. J u l y 1892.. July: 18Y4.. July, 1896.. July, 1q.96.. July, 1897.. July,lYOl.. July 1907.. July' 1907. July: 1907.. dug 1878.. Aug' 1879.. Aug:1879.. Aug. 1684.. Aug'lW.. Aug"18y1.. Aug::1898.. Aug 1905.. Aug'1905.. Aug.' 1907.. Bept ' 1879. . Sept::lB96.. Oct 1876.. cjci.' 1 ~0 .. Oct.: 1893.. Nov., 187X.. Nor., lW3. . Nov. 1900. No".' 1900.. Nov.:1905.. Nov., 1906.. Nor., 1906.. Dee 1875.. Ilec' 1879.. 1)ei: IXHII.. Der., 1905.. .Tuly, 1906.. bUg.,IR#J.. PeIJt., 1905. . act.' IW. De,:., 1873.. I..'..' ..... ..... ..... , ........... , I . . . . . , . . . . . , ..... I ...... .....I ...... 2.64 1s ..... ..... . .. .. . . .. .. 5.W 4 4. I9 20-21 . .. . . . . . . . . . .... . . .... ...... ..... . .. .. . . .. . . . . . . . . . .. . . ..... ..... 2.97 15-16 3.78 24-25 2.87 26-29 2.87 '20-21 2.&2 2 3.68 5-9 ...... ..... .. .. . . .... . . . . . . . . . . . 2.3Y 2 3 2.74 27-28 4.12 2Y 15 . .. .. . .. .. 8.27 % . . . . . . . . . . .,.:iA 2 6 -2 ~ 3. 88 2-3 -. 81 26-27 2. 91 ?I-"? 5.16 2W21 2.31 24-25 2.81 25-29 2.85 17-18 3.15 19-20 2.99 ?%24 :;. 07 2%24 2 .~~3 4 2. W 1-2 3.87 :I Apr ., 1872... Apr IBSO... Api:l883 ... Apr. 1887.. . Apr ' 1892.. . May' 1872.. . Mas! 1873.. . .....I ...... 3.56 8 ..... 4.06 1.5-16 ..... p.64 5-6 ..... 3.28 22-?3 . .. .. 2.50 20421 . . . . . . .. . . . . . . . . . n. 39 . .. .. . . .. .. . 1. :U ..... I ...... 1:ou "3 015 I 81 . MG' 1906.. . . . . . . . . .. .. . May: 1906.. . . . . . . . ._ _. May I-... ...... ..... . May' 190s.. . . .. . . . . . . . . . J n n i 1874... 3.02 3 Jun41878.. . 2.92 17 June.lBR1.. . . . . . . . . .. . . . June ix9n.. . . .. .. . . .. .. . Junilk9U.. . . .. .. . . .. . . . Junell895 ... 2.66 19-1 June:I596 ... 2.87 B2-8 1 .3 ..... ..... 1. ux 1.w 0.83 0.66 U.55 0. 67 ..... 0.95 11. 78 1 .2 0.84 0.51 1.00 ..... , . . . . . . . . . I . . . . . . . . . . 030 4:ou I:% 0:lR 0:s 030 , . . . . . ..... ...... .....I ..... . . . . . . . . . . . . . . . . . . . . . 1 2 ; 23 20 . . . . . . ..... ..... 0:40 U50 i:n5 .......... I ..... , 25 1 ?i Excessive amounts for short periods. ..... O:l8 11:'?s n:?o u:zn - -1 I 0 a 4 - .... 2. ou 1.w ?. 70 1. L9 1.39 1.1:; 0.59 a 61 n. 79 n. M 0. %3 .... .... .... .... !: : 2.66 0. 60 1.00 0.54 0.65 .... .... .... .... .... .... .... .... .... .... 1.00 .... .... .... .... .... .... .... ..... . 31 4 31 ti I . . . . . . . . . . . , . . . . . . . . . . . . . . , . . . . . , . . . . . . . . . . 046 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 0 3 i 027 1:W 0:40 0:05 U10 27 16 15 19 4 23 ' ----./' -- 0.4iG" 0. 4861 n. ~ti7-1 n. 5 1 1 ~ n. .mi; n. WII TABLE 2. NUMBER OF EXCESSIVE PERIODS OF RAINFALL. 1872 ....... 3 1881 ....... 1 1890 ....... 3 1899 ....... 0 1873 ....... 3 1882 ....... 2 1891 ....... 1 19 UO....... 2 1874 ....... 0 1883 ....... 4 1892 ....... 2 1901 ....... 2 1875 ....... 3 1884 ....... 1 1893 ....... 1 1902 ....... 2 1876 ....... 2 1885 ....... 1J 1894 ....... 1 1903. ...... 1 1877 ....... 1 1886 ....... 0 1895 ....... 1 19 M....... 0 1878 ....... 3 1887 ....... 1 1896 ....... 5 1905 ....... 8 187 g ....... 4 1888 ..... .1 1897 ....... 2 19 0 6 ....... 6 1880 ..... .5 1889 ...... .1 1898 ...... .3 1907 ....... 5 RECAPITULATION BY MONTHS. January.. . . . . . 3 May.. . . . . . . . .I 1 September.. . . . 3 February ...... 3 June ... ...... 12 October ...... .. 4 March ......... 3 July ....... . ..la November ... .. 7 April ........ .. 5 August .... . ..11 December ..... 5 1872-1880, inclusive . . . . .24 1891-1900, inclusive. . . . .18 1881-1890, inclusive . . . . .I4 1901-1907, inclusive. . . . .24 BECAPITULATION BY PERIODS. . . . . . ..... . . . . . . . . . . . . . . . I . . . . . A NEW FORMULA FOR COMPUTING THE SOLAR UON- STAN" FROM PYRHELIOMETRIU OBSERVATIONS. By H. H. KIMBALL. [Read before the U. 5. Weather Bureau Committee, April 29, lW6.] An attempt has been made to develop an empirical formula By means of which the solar constant may be computed from pyrheliometric observations with an accuracy comparable with the accuracy of the -observations themselves. As suggested by Angstrom,' if we express the coefficient of general atmospheric transmission for any wave length by the equation and the corresponding intensity of solar radiation by then the radiation received at the surface of the earth after the solar rays have past thru an atmospheric diffusing layer of thickness ni will be exprest by Q,, = f k r (I ) [a (I )] d I . . . . . . . . . . . . . . . . . (3) Since the function Y (I ) is not exprest by any known law, the problem may be simplified by assuming a dispersion, c, that will give a solar spectrum of constant intensity. Such a dis- persion has been computed from Abbot's values of the intensity of the normal solar spectrum outside the atmosphere.' (1) (2) Y A =P (I ) ..-............. .... &= v(I) ..................... m 4 Equation (3) now takes the form- =a Q, = J[y (a)]'" d z . . . . . . . . . . . . . . . . . . (4) ;r, TABLE 1.- Vdicul tranamitlsion of atmoephers. . . . . . . ..... . . . . . . . . . . . . . . . . . . . . .. .. . U.P#:! 0.3987 0.4091 0.4145 0. 40187 11. u1:::; 0. U l i l 0.0'245 u. 0:w 0.04% 0.0541 0.0641 0.0751 0.0866 0.857 0.1132 0.1267 0. I427 u. 15Y5 n. I 777 0. 1962 n. 21+1 n. W E n. 2576 n. 2818 11. 3K:r 0.3346 11. :