April 23, 1887.1 



SCIENCE. 



391 



ent points, a series of lines will be found, all of 

 which theoretically pass through the centre of gravity 

 of the figure. 



Both of these methods have been tried on the 

 map of the United States, and with the following 

 result : — 



A base map of the United States (scale about 112 

 miles to the inch) was cut out along the boundary, 

 and the map so cut out suspended by a pin stuck 

 through it. From the same pin a plumb-line was 

 suspended. The map was swung upon the pin, and 

 allowed to come to rest several times, and its mean 

 position inferred. A line was then drawn on the 

 map, representing the projection of the plumb-line 

 upon the map in its mean position. 



This process was repeated in several positions of 

 the map, and a series of intersections determined. 



Northernmost latitude (Minnesota) 49° 24' 



Southernmost " (Florida) 24° 23' 



Mean latitude 36° 54' 



Northernmost latitude (Alaska) 71° 22' 



Southernmost " (Florida) 24° 23' 



Mean latitude 47° 53' 



each intersection representing the centre of gravity, 

 resulting from a pair of observations. 



The centre sought was then assumed from an in- 

 spection of these points. From this adopted centre 

 a circle with a radius of about one-sixteenth of an 

 inch (some seven or eight miles in nature) would 

 include all points excejjt two resulting from very 

 acute intersection, and which were rejected. 



Again, a similar map was mounted on stiff card- 

 board, and then cut out along the boundary, as before. 

 This was then balanced on the point of a spindle It 

 was balanced with the face of the map down, and 

 then with the face up ; and both balancings agreed 

 in locating a point not differing visibly from the 

 point determined by the preceding method. 



This point, which according to one definition is the 

 centre of the United States (Alaska excluded), is 

 situated in latitude 39". 8 north, and longitude 98°.8 

 west of Greenwich. Platting this position on the land- 

 office map, the point is found to be in Cora townshijj, 

 Smith county, Kan., some ten miles south of the 

 southern boundary of Nebraska, and a little to the 

 westward of the middle of the state of Kansas. 



These methods are directly applicable only to cases 

 where the desired point is included in the given area. 

 Such is the case with the United States, excluding 

 Alaska. 



If, now, we are to determine the centre, including 

 Alaska, it will be necessary to determine the geo- 

 graphical centre of Alaska, and then determine, on 

 the line joining these two centres regarded as a 

 lever arm, the fxilcrum between weights propor- 

 tional to the areas of the United States alone, and 

 of Alaska alone. 



The centre of Alaska was found by the suspension 

 method onl3^ The intersections were all closely 

 accordant, and locate the centre on the head waters 

 of the Kuskokwim River in latitude 63°. 4 north, and 

 longitude 151 ".5 west. The map used for the pur- 

 pose was the base map of Alaska and adjacent regions, 

 prepared some years ago by the coast survey. 



These two centres found, as above described, 

 were noted on a base map of North America, and 



joined by the projection of an arc of a great circle. 

 This line was then divided into parts inversely pro- 

 portional to the respective areas of the United States 

 alone, and of Alaska alone ; and the point so found 

 is adopted as the centre sought. For this purpose 

 the area of the United States was taken as 3,026,000. 

 and of Alaska, 583,000 square miles. The centre is 

 found to be in latitiide 45°.0 north, and longi- 

 tude 103°. 5 west from Greenwich ; which locates 

 it near Slave Butte, Dakota, some twenty-five miles 

 east from the boundary montiment between Dakota, 

 Montana, and Wyoming. 



If we assume that the geographical centre is de- 

 termined by the intersection of a parallel and merid- 

 ian, which are the means of the extreme latitudes 

 and longitudes, then we shall have for the United 

 States, excluding Alaska, — 



Easternmost longitude (Maine) 66° 57' 



Westernmost " ( ^^ashiugton Territory) 124" 47' 



Mean longitude 95° 52' 



and, including Alaska, — 



Easternmost longitude (Maine) 66° 57' 



Westernmost " (Alaska) 187° 32 



Mean longitude 127° 14' 



In the first case (exchiding Alaska) the centre lies 

 in the Indian Territory, some seven miles from the 

 southern boundary of Kansas, and about twenty-five 

 miles a little west of south of Independence, Mont- 

 gomery county, Kan. 



In the second case (including Alaska) the centre 

 is found to be in the Pacific Ocean, about one hun- 

 dred and twenty-five miles a little south of west 

 from Cape Flattery. This rather startling result 

 brings into conspicuous notice the extension of the 

 Alaskan possessions to the westward. 



The only reference to the geographical centre of 

 the United States that has met our notice is con- 

 tained in the ' Fourth biennial report of the state 

 board of agriculture to the legislature of the state of 

 Kansas,' where it is stated, on p. 493, that " Kansas 

 is the central state of the Union, the exact geograph- 

 ical centre of the United States being at a point lying 

 within a few miles of the centre of the state.''^ 



Maecus Bakee. 

 Washington, D.C., April 15. 



Death of Dr. Albert Kellogg. 



Among the recent deaths of scientific men, that of 

 Dr. Albert Kellogg, the veteran botanist of the 

 Pacific coast, is made known in the San Francisco 

 papers. 



He died in Alameda, Cal., on the 31st of March, 

 at the age of seventy -four years. He was a native of 

 New Hartford, Conn. For over thirty years Dr. 

 Kellogg has been identified with the botany of Cali- 

 fornia and the adjacent region, commencing Sept. 4, 

 1854, when he exhibited a drawing and specimen of 

 a plant from the " salt marshes of the Bay of San 

 Francisco, the Frankenia grandifolia," at a meeting 

 of the California academy of sciences, of which he 

 was one of the founders. During all these years he 

 was constantly active, either in the field or the her- 

 barium. He was exceedingly skilful with his pencil 

 and brush in rendering from nature, and up to 

 nearly the last moment was engaged in making draw- 

 ings of the floral and sylvan species of the Pacific 



