82 SHEEP HUSBANDRY IN THE SOUTH. 



'variable — exhibits 7nore sudden and greater extremes, than the climates of 

 New- York and New-England. The weak and easily prostrated muscular 

 and vascular system of the sheep, will better endure great extremes of con- 

 tinuous heat or cold, than rapid and marked variations in temperature. 

 Subjected to the latter, catarrh not violent enough to kill in its inflammato- 

 ry stage, but assuming a chronic form — and followed by a slow and wast- 

 ing debility, frequently attacks flocks. Sometimes it assumes an epizoo- 

 tic and malignant character — as during the past winter — and sweeps away 

 thousands of sheep. 



The isothermal line (or line of equal mean heat), does not vary particu- 

 larly between the same latitudes in New-York or Wisconsin — or between 

 Virginia and Missouri. But as we leave the ocean and other large bodies 

 of water, the isotheral and isocheimal lines are found to diveige more 

 and more from the isothermal one — and the range of the thermometer (the 

 extremes of heat and cold indicated by it), rapidly inci'eases. The follow- 

 ing Table of temperatures, kept by officers in the Army, for a series of nine 

 years, is from Doct. Forry's excellent work on the " Climate of the United 

 States, &c."* It strikingly illustrates the fact asserted. The four points 

 specified are in about the same latitude. 



Doct. FoiTy states that the mean annual range of the thermometer at the 

 following places, is as follows : at Fort Sullivan (Eastport, Me.) it is 104°, 

 while at Forts Snelling (confluence of the St. Peter's and Mississippi in 

 Iowa) and Howard, (Green Bay, Wisconsin,) in about the same latitude, it 

 is respectively llO'^, and 123°. 



At Fort Preble (Portland, Me.) Fort Niagara (near the mouth of the 

 Niagara River, N. Y.), Fort Constitution (Portsmouth, N, H.) it is 99°, 

 92°, and 97° ; at Fort Crawford, (confluence of the Wisconsin and Missis- 

 sippi Rivers in Wisconsin,) on the same parallel, it is 120°. 



The above instances are not isolated ones. The same law is found — 

 other things being equal — to generally prevail throughout our own, and 

 perhaps all other countries.t 



While the cold of the Noi'thern, and particularly the North-western- 

 States, so greatly exceeds that of the Southei-n States, few would be pre- 

 pared for the proposition that the extremes of heat in the formex', often 

 reach points unknown many degrees farther South ! Yet such is the 

 fact ! 



Fort Snelling, in latitude 44° 53', and occupying a central position in that 

 vast temtory lying between the Great Lakes and the Missouri, and between 

 the 41st and 49th parallels of latitude — and which may therefore be pre- 

 sumed, to a certain extent, to afford a type of the climate of that whole re- 

 gion — feels a maximum summer heat of 93° — the same with that of Wash- 

 ington City, in latitude 38° 53', and Old Point Comfort, Va., in latitude 

 37° 2'. At Port Johnston, on the Coast of North Carohna, in latitude 34°, 

 the maximum heat is but 90° ; at Fort Moultrie, in Charleston Harbor, 

 in latitude 32° 42', it is also 90° ; at Fort Marion, St. Augustine, Florida, 



See the above named work. p. 43. I am also indeotcd to Doct. Fony for all the records of thermometii- 

 cal observations, al the U. S. military posts, which are subsequently quoted. 



_ t Local exceptions exist, owin^' to the prevailinn; winds and other causes. For example, Fort Howard 

 18 much nearer a large body of water than Fort Snellin''. Altitude also exerts its influence. 

 (178) 



