HORTICULTURAL SOCIETY. 103 



Eockies, where they follow in the lee of the mountains, which 

 turn upward and beyond the reach of interference the warm 

 currents from the Pacific, and, facilitated in their movements 

 by the great treeless plains, until they reach the track of the pre- 

 ceding low barometer. As the low invariably moves to the 

 northwest, the high, with its cold, naturally follows. Thus, we 

 have the phenomenon of cold weather coming to us from the 

 west or southwest. 



You will readily see, from the facts I present you, how you, in 

 common with the people of Dakota hold the gateway through 

 which these storms must enter the territory of the United States, 

 and how, by the suggestion already made, you may greatly 

 ameliorate the climatic conditions of the whole country, for I 

 have no possible doubt, but that through the reforestation of the 

 great western plains, a very perceptible influence, for the better 

 may be wrought, upon our climate. 



I will now hurriedly illustrate, by the use of a set of tridaily 

 signal service charts, the movements of the storm under consid- 

 eration. As already stated, you will notice the ink-spot on the 

 chart in eastern Colorado, which marks the centre of the low 

 barometer at 3 p. m. of January 6th. The dark wavy line across 

 the upper portion of the chart, indicates the line of zero tem- 

 perature, at that hour. The almost unchanged position of the 

 zero line, in the lake region, during the prevalence of this storm 

 will illustrate the beneficial influence they exert upon the cli- 

 mate, a fact which gives to Michigan and the surrounding ter- 

 ritory, its just renown as a superior fruit growing section. 



Turning to our next chart, which represents a period eight 

 hours later, we find that the centre of the low area is now near 

 Fort Sill in the Indian Territory, and that the zero line has 

 dropped down, from Fort Custer to Denver, while all the Gulf 

 region is basking in a temperature much above the frost point. 



The next chart, which is for 7 A. M. of the 7th, represents, as 

 you will see, the centre of the low barometer as near Indianola, 

 Texas, and the zero line at Santa Fe and Fort Elliott, but almost 

 unchanged as to the Lake region. The temperature of the Gulf 

 coast is 40° and upwards. 



This chart, which is for 3 P. M., shows the centre to be in the 

 Gulf of Mexico immediately south of Indianola and off the mouth 

 of the Eio Grande. The zero line has also dropped down, and 

 that too against the tempering influence of the sun, from Fort 

 Elliott to Fort Sill, while the temperature of the Gulf coast, 



