2 



to receive communications, if possible, from all inhabited portions 

 of North America, especially from the stations of the Hon. Hud- 

 sou's Bay Company. And with this view it has obtained the 

 sanction of the proper authorities for an application to the officers 

 of the Company for assistance, as shown by the accompanying 

 letter of Sir George Simpson, Governor of the H, B. Territory. 



The attention of the friends of science is therefore respectfully 

 invited to certain points, which will be referred to more fully 

 hereafter. In an accompanying package will be found detailed 

 instructions in regard to making and recording observations, and 

 it is only necessary here to indicate a few subjects which are of 

 more particular interest. 



1st. The beginning and ending of storms of wind and rain, and 

 the time when the sky is overcast. Records of this kind enable 

 us to map the face of the heavens over a large surface of country, 

 and to determine the extent of a cloud, or of falling rain, snow, &c. 



Beside the regular variations of the meteorological instruments, 

 special information is desired as to the occurrence of thunder 

 storms ; the time of day at which they take place ; the direction 

 from which they come ; their duration and intensity ; notice of 

 trees or other objects which may be struck by lightning. 



2d. Tornadoes, land and water-spouts, and whirlwinds. The 

 width of the path along which the mechanical effects are pro- 

 duced; the direction of the path; the appearance of the tornado 

 at a distance ; the motion of the clouds over the head of the 

 observer as the tornado approaches and as it recedes from him. 

 Note whether any electrical phenomena are exhibited, such as 

 thunder, lightning, and luminous appearances ; the mechanical 

 effects, prostration of trees, and translation of heavy bodies. 



3d. The aurora borealis: time of its beginning and ending; 

 time of the formation of arch, beams, and corona; and whether 

 there is a dark cloud below the arch ; and other points mentioned 

 in the pamphlet of instructions, 



4th. Time of early and late frosts, particularly first and last. 

 Depth of ground frozen, in feet and inches ; disappearance of 

 frost from the ground. 



5th. Time of closing and opening of rivers, lakes, streams, &c., 

 and any other phenomena relating to temperature. 



A single register of any one of these phenomena carefully made, 



