November 18, 1898.] 



SCIENCE. 



711 



Dates given in the Julian calendar must first 

 be transformed to the Gregorian calendar be- 

 fore applying the above formula, and this trans- 

 formation is readily effected through the rela- 

 tion 



N 



4 



G = J+ {N—2)- 



where G and J are the respective dates, N is 

 the number of the century, and the remainder 

 is to be neglected in the division by 4. 



Geo. C. Comstock. 

 Washburn Observatory, 

 Madison, Wis., October 31, 1898. 



NOETHEEN EOCKY MOUNTAIN GLACIERS. 



To THE Editoe of Science : For some years 

 I have been interested in the geography of a 

 small section of the Rocky Mountains which, 

 until recently, was part of the Blackfeet Reser- 

 vation, in northwestern Montana. This section 

 lies, for the most part, east of the Continental 

 Divide and between the international boundary 

 on the north and the Great Northern Railroad 

 on the south. The portion of it which I know 

 best is included in the watershed of the St. 

 Mary's River and its tributaries. In 1891 I 

 took to the head of the St. Mary's River the 

 first party that had ever visited it, so far as 

 known, and in 1895 accompanied to the same 

 point the Government Commission which after- 

 wards purchased from the Blackfeet Indians 

 the rough mountain land which formed the 

 western portion of the reservation of that tribe. 

 Before that I had made a sketch map of the re- 

 gion, which is the basis of all the maps of it 

 that have been made or published. 



In 1897 I made a hasty trip to the head of 

 the river and climbed Mt. Jackson, the highest 

 peak in that region. Last July (1898) I again 

 went to the head of the river and climbed the 

 Blackfoot Mountain, another lofty peak some- 

 what less accessible than Mt. Jackson. On 

 both trips 1 was accompanied by my friend, 

 Mr. J. B. Monroe. 



These last trips have enabled me definitely to 

 locate two points about whose relations I have 

 never until now been quite certain. One is the 

 Pumpelly glacier, discovered by Professor 



Raphael Pumpelly, who, I believe in 1883, with 

 a small party which included the late W. A. 

 Stiles, crossed from the Flathead country to 

 the Plains by way of the Marias, or, as it is now 

 called, the Cut Bank Pass. This great mass of 

 ice, which is seen by every traveler going 

 through the Cut Bank. Pass, rises to the height 

 of several hundred feet above the face of a 

 lofty cliff, over which portions of the glacier 

 are constantly falling with tremendous reports, 

 which are heard for a long distance. 



From the top of the Blackfoot Mountain the 

 whole country leading up to the Cut Bank Pass 

 can be seen, and immediately below it to the 

 southeast lies the Pumpelly glacier, readily 

 identified not only from its position with rela- 

 tion to the valley, but also by the peaks and 

 rocks in its neighborhood. It thus appears that 

 the Pumpelly glacier, as I have long supposed 

 was the case, is part of the southern flow of the 

 great ice cap which covers almost the whole of 

 the Blackfoot Mountain. The Blackfoot glacier, 

 which stretches away in a northeasterly direc- 

 tion from the peak of the Blackfoot Mountain, 

 though perhaps varying in extent somewhat 

 with the season , was estimated last July to be six 

 or seven miles long, and in some places between 

 three and four miles wide. From the peak of 

 the Blackfoot Mountain the ice field flows also 

 in a northerly direction, meeting another which 

 runs down between Mt. Kainah and Mt. Jack- 

 son, while from Mt. Jackson a number of smaller 

 glaciers flow down to timber line. 



A little to the west of south of the Blackfoot 

 Mountain and lying in a great bend of Mud 

 Creek — tributary of the Flathead — which 

 entirely cuts it off from the main range, lies 

 Mt. James, one of the three highest peaks in 

 this immediate section. Seen from the east, it 

 is shaped like the square-faced, peaked end of a 

 hay stack, and at a distance appears very diflB- 

 cult or impossible of ascent. Its southern and 

 western faces may be more practicable than 

 those on the north and east appear. From the 

 top of the Blackfoot Mountain the level shows 

 Mt. Jackson to be the highest of all these moun- 

 tains ; Mt. James the next, while Blackfoot is 

 the third. But the differences in height are 

 very slight. 



A few miles northwest of Mt. Jackson, and 



