82 DAVENPORT ACADEMY <>F NATURAL SCIENCES. 



Not only is the number of reporters inadequate, but the reports are 

 not always exact in the matter of time. This is of great importance, 

 as errors in time records render it impossible to properly combine ob- 

 servations in making up the history of the storm. Some reports are 

 valueless, on account of not being dated. The reports would be of 

 much greater value with temperature observations and barometric read- 

 ings. New blanks should have spaces for these, although all observers 

 may not be able to make such record. 



The circular and blanks were copied after those used by the signal 

 service in 1886. They read as follows: 



DAVENPORT ACADEMY OF NATURAL SCIENCES. 



TlirNDER-STORM OBSERVATIONS IN IOWA. 



M , , Iowa. 



Dear Sir : Knowing you to be interested in meteorology, from your being a 



, I address this note to you, asking if you will not undertake to report all 



thunder-storms occurring at your locality during this season, from June 1 to 

 September 1. Certain suggestions follow. The fuller the report the better, 

 though all the questions absolutely necessary to answer are on the enclosed 

 blank. 



Count storms six hours or more apart as different storms. 



Note the time of first thunder, last thunder, and loudest thunder. 



Note direction from which the storm comes, and that to which it goes. 



The "scale" of intensity of storm is: I. Distant lightning. 2. Distant 

 thunder. 3. Moderate thunder-storm. 4. Heavy thunder-storm. 5. Heavy, 

 with high wind. 6. Tornado. 



Give length of time of rain. 



Catch rain in a pail or can with vertical sides, and measure with rule. 



Give particulars as to amount of hail, size and shape of stones, etc. Also 

 time of its fall. 



Much value attaches to full descriptions of clouds. Such reports are very 

 interesting, though not absolutely required. 



Scale of force of winds: o. Calm. 1. Light, moving leaves of trees. 2. 

 Moderate, swaying branches. 3. Brisk, raising dust. 4. High, blowing twigs 

 from ground, swaying trees. 5. Gale, breaking branches, loosening chimney 

 bricks. 6. Tornado, destructive. 



Be sure to note every storm heard or seen, even though distant; its direc- 

 tion and time, if nothing more. Give details of lightning strokes. 



A sample blank is enclosed. Each is for three storms. When filled, they 

 are to be kept until five have accumulated, or until the end of the month. Then 

 all are to be sent on. 



Use "standard" time. Be as exact as may be to the minute. Always date 

 carefullv, and indicate morning or afternoon by A. M. and i\ M. Always write 

 in the blank the place of observation. 



Please let me know at once if you will assist. I enclose card for your 

 reply. Address Prof. F. Stark, 



Cedar Rapids, Iowa. 



