Missouri Botanical Garden PETER H. RAVEN LIBRARY Pagination Note: Since many of the items lack a specific page number, the page number displayed online refers to the sequentially created number each item was given upon cataloging the materials. cm cm VSE? Missouri Botan ical Gar den cm 2 3 4 5 6 7 8 9 10 copyright reserved cm Missouri Botanicai. ^ ■ George engelmahh Papers. 6 7 8 9 10 Missouri Botan ical copyright reserved garden Cl ct 2J> ^ ,-iJA ~ */> ^ C!Vv «,vX-*3 ^f« ..Cp, V«j 0 .. .^> 'O-'^yt t A J'.. ft *v/ 0 1 2 3 4 5 6 7 8 9 10 Missouri Botanical copyright reserved garden cm ft vq * C <*/u^ * ftU'f J/^vyLj j ,- T Ar’* ii^^t /<*•<« #!*'**•'*• ' f~ ? , J | r * _ o. y x«* .)' . ^ cm Missouri George Botanicai. ENGELMANR GARDEN PAPERS ’ ' < ' & ' - ! -* BOTAN ICAL cm copyright reserved garde .s&m% BOTAN ICAL cm copyright reserved garde cm Missouri botanic*.' GEORGE ENGELMANN Garden Papers CjiffcU. /v^*-** « ^ . — 9 " ^ ^ , J> 'A*U^yr- 6W PAPERS Botan ical copyright reserved garden cm s, St. Louis. Missouri peers' GEORGE EN6ELM- > •' 0 1 cm 6 7 8 9 10 Missouri . . . Botanical copyright reserved garden cm '/ /K // - o# ■*■ o.Xxo.f -..„ /’■v 840 A~^ A ilii cm Missouri George BOTANY wrg Engelmann papers 6 7 8 9 10 copyright reserved 841 U Wfi 6 7 8 9 10 copyright reserved V * 10 «4 — .Z C?in. /| ixC y 9#_~ ^ c^- <*v-i2) 843 cm George Botanical- Garden Engelmann Papers. Missouri Botan ical Gar den 6 7 8 9 10 copyright reserved W- & 118 TRANS. OP THE ACAD. OF SCIENCE. 4 T <0 ^ interrupted descent and ascent took place from January to December, we find in 1862 some interruptions in the steps of that ladder. The electricity in February, 1862, is about four degrees higher than that of January, April somewhat higher than March, and July is the lowest instead of September in 1861. These trifling irregularities may be accounted for by differences in temperature and relative humidity, and by a greater number of thunderstorms in 1862. January of 1862, for instance, was so unusually rainy, that its relative humidity too was unusually high, diminishing thus electricity. But the general features of distribution of electricity throughout the year are apparent in both years, and we may in that re- spect divide the twelve months of each year into two or three groups. Computing the months which give the highest; elec- tricity and those which give the lowest in each year, we find that in both years the months of January, February, March, April, November and December exhibit the highest, and the months of May, June, July, August, September and Oc- tober the lowest electricity. The first group gives The aggregate monthly mean of 71.5 degrees of electricity in 1861 and 74.6 “ “ “ 1862 : While the second group gives 29.0 “ “ “ 1861 , and 25.7 “ . “ “ 1862 The second group prevailed therefore in 1861, and the 1st * " Or" we may TIT vide the twelve months '"of enchl year into three groups. The first group with the highest electricity is formed by the months of January, February, November and December ; the second with a mean electricity by the months of March, April, May and October; and the third with the lowest electricity by the months of June, July, August and September. The aggregate monthly mean of The first group in 1861 i The second * “ “ The third “ * ; 52.9— in 1862, 54.6 33.5 “ 35.2 14.1 “ 10.5 Thus in 1861 the third group prevailed, and in 1862 the first and second. But* these differences are so well balanced throughout the year, ‘that the mean of the whole year in 1861 and in 1862 is exactly the. same, namely, . Such an identity in the yearly result, even to* decimals, , is of course not to be expected every year; but. it seems to prove, at least, that the yearly mean of electricity is as constant as that of temperature, of relative humidity, and of atmospheric pressure. * ». The third 4able, showing the daily periodicity of atmos- pheric electricity, confirms the daily two maxima and two minima of electricity as an undeniable fact. 0 1 2 3 4 5 6 7 8 9 10 Missouri BOTAN ICAL cm copyright reserved garden r WISLIZENUS — ATMOSPHERIC ELECTRICITY. 11 T VI. The appearance of negative electricity was connected in 1861. 1862. . No. times. No. times. 30 32 * with thunderstorms. 23 28 with rains without thunder and lightning. 20 4 with dry storms (without rain and without thun- 4 3 der and lightning), with snow. 1 0 with fog. 78 67 | VII. Relation of Rain and Snow to Electricity . Rain without thunderstorm was accompanied January..... February . .. March April May June July Aug'ust .\.V. , September.. October ..... November ., December .. By Positr ve Electri- fy- By Negative Electri- city. By no Electricity. In 1861. In 1862. In 1861. In 1862. In 1861. In 1862. 7 ...... 5 ...... 3 ...... 2 2 2 ...... 1 ...... 4 1 5 ...... { \ 4 8 1 6+.... /i 11 1 lo m&i 7 1 1 3 1 ...... 3 3 I ...... ~1 2 ...... 4 1 4 8 ...... 3 1 1 1 7 1 2 ...... 3 7 7 2 3 6 50+ el. 36 + el. 23 — el. 28— el. 15 no el. 34 no el. Snowing was accompanied By Positive Electri- city. By Negative Electri- * city. By no Electricity. In 1861. In 1862. In 1861. In 1862, In 1861. In 1862. January February March 3 ...... 12 3 ...... 12 2 1 October.. 1 November December 5 4 2 2 1 |23 + el*. 36+ el. 2—^ el. 3 — el. 1 no el. REMARKS. The monthly mean of atmospheric electricity in 1862 was not quite so regular as that in 1861. While in 1861 an un- r o S'' Is- 7 8 9 10 Missouri Botan ical copyright reserved garden cm 0 1 2 3 4 5 6 7 8 9 10 Missouri Botanical cm copyright reserved garden cm //f f-v ~ fife* 845 M» | cm BOTANICAL GARDEtf . \ fiEORGS ENGELMANN PAPE«* 6 7 8 9 10 Missouri BOTAN ICAL copyright reserved garden cm MISSOURI GEORGE Botanical ENGELMANN Garden papers BOTAN ICAL cm copyright reserved garden