OF ARTS AND SCIENCES. 343 



Intensity on a scale of three (0, 1,2); wind force on scale of twelve. 

 No temperature records. Especial attention is given to the appearance 

 and effects of lightning. Reports are made on postal cards. 



Switzerland. Observations systematically begun in 1883 ; reduced 

 by Mantel and published in the Annalen der schweizerischen meteoro- 

 logischen Central- AnstalL About 140 stations besides the regular 

 stations of the Swiss weather service. 2,689 reports in 1883. 



Observations : time of first and last thunder ; of passage over zenith ; 

 of beginning and ending of rain and hail ; direction of storm's origin 

 and disappearance; direction and force of wind before, during, and 

 after the storm ; notes on rain-fall and damage by storm. 



Intensity on a scale of six ; direction recorded to octants ; no obser- 

 vations of temperature. The records are made on franked postal cards. 



United States Signal Service. Investigation of thunder- 

 storms by volunteer observers, organized by Prof. H. A. Hazen in 

 1884; records of more than 13,400 storms were obtained for this 

 year, and a report thereon is to be sent to all observers. 



Observations : thunder, first, loudest, and last ; direction of storm, 

 coming from and going to ; time of first atid last rain and hail, and 

 amount ; direction and force of wind before and after storm ; distant 

 lightning ; and remarks. 



"Thunder-storms twelve hours apart maybe taken as separate storms." 

 Intensities on scale of five. Reports are made on a special " penalty 

 card," addressed to the Chief Signal Officer of the Army. 



In reviewing the reqiiirements thus summarized, the absence of a 

 sufficient correlation of the several objects of observation, and the 

 general omission of temperature records, seem to me serious defects in 

 the plan of work. Certainly the relation of temperature to wind, of 

 surface wind to cloud-motion, of wind and clouds to rain, etc., can be 

 much better determined if at certain times records are taken of all of 

 these different phenomena. We have therefore aimed to secure ob- 

 servations of wind, temperature, rain, clouds, etc., all together, several 

 times during every storm ; the times being determined by the occur- 

 rence of the first thunder, the first wind-squall, the first rain, the loudest 

 thunder, and the last rain ; and also by the even half or quarter hours, 

 as already described. Our records as proposed for the coming summer 

 may therefore be thus summarized. 



Summary of Instructions to Neio England Observers. — Class A. — 

 Required: time and direction of first and loudest thunder, whether 

 rain falls or not ; time of first, heaviest, and last rain, and estimated 

 amount, whether with thunder or not ; intensity of storm on scale of 



