14C 



FARMERS' REGISTER. 



[No. 3 



tageous. By artificial cold, we may guard the 

 eifgs or?ilk-\vorms from hatching too soon for the 

 full supply of Ibnd ; but it i/s only a natural climate 

 of sufficient rigor in winter that will keep back the 

 springing of the mulberry leaves, Ions' enough to 

 avoid such spring li'osts as are common in the 

 south of France, and even in Lombardy. From 

 these different causes, it follows that the destruc- 

 tion of niullierry lea\es by late frosts, which is a 

 calamity so frecjuent in those delightful and warm 

 climates, will be oi' very rare occurrence in Vir- 

 ginia. And, to extend the ground of remark, it 

 may be safely inferred from the several positions 

 assumed, (if they are considered as maintained,) 

 that in no part of the United Stales is the rigor of 

 winter any obstacle to silk-culture, unless the mul- 

 berry trees (while vegetation is dormant) are 

 killed or injured by the cold ; nor the long duration 

 of winter weather, except so far as shortening the 

 lime for growth, and lessening the summer's pro- 

 duct, of the mulberry leaves. Neither is it supposed 

 that hi the most southern states any importimt ob- 

 stacles of opposite character will operate; for 

 though the mild winters there will hasten vegeta- 

 tion, steady warm weathe.- succeeds as early in 

 proportion ; and the summer is there long enough 

 to raise several successive crops of worms, and 

 yet pretermit the time of excessive heat which 

 would be injurious to their health. 



There is anollier view of i his part of the subject 

 which deserves more consideration than the inci- 

 dental nolicfe taken of it above. The remarkable 

 differences of temperature in the same latiiudes. 

 which are formd to exist on the opposite coasts of 

 the Allautic. are also Iband on the opposite sides 

 of the Pacific ocean. Thus the eastern coasts, 

 both of North America and of Asia, are much 

 colder, in mean temperature, than the western 

 coasts of bolli continents in the same laiitr.des. 

 This is not the place to discuss the causes; but the 

 effects are known to be as just stated.* Hence, it 

 might be inlerred, in the absence of facts (or evi- 

 dence, that the climate of the United States, both 

 in mean temperature and in extremes, is much 

 more like that of the same latitudes of China, 

 which is similarly situated on the western side ol 

 an ocean, than either is to the climate of any part 

 of Europe; and this position is also sustained by 

 unquestionable facts. This conclusion then, to 

 which we came both by way of reasoning and 

 experience, furnishes additional strength to my 

 position, that the climate of Virginia is belter for 

 silk-culture than the best in Europe. For in Chi- 

 na, though vviih less advantage of the improve- 

 ments of art or science, the business is undoubt- 

 edly conducted with more success than in any 

 part of Eurojje; and therefore, as well as for the 

 other reasons staled, it will scarcely be doubted 

 that the climate of China is among the best for 

 this purpose. ° 



The cold of winter is no injury to the ffrowth 

 and product of mulberry trees, unless it i^so se- 

 vere as to kill their branches; and that is not to 

 be feared in Virginia, even for the most tender 

 kind, nor indeed much farther north. On the con- 



* See this subject treated in an 'Essay on the 

 Climate of the United States,' which was reviewed' at 

 page 599, vol. iv. Farmers' Register. This essay, 

 which was first published thirty years ago, was writ- 

 ten by the late John Wickham, esq. 



trary, a considerable degree of cold in winter is 

 beneficial, by preserving the dormant condition of 

 the trees, and preventing the too early putting 

 forth of the leaves, and their consequent exposure 

 to the spring frosts, which are so oflen fatal in the 

 south of France, and even in Lombard}', after 

 Vi^inters so mild as not to endanger the growth of 

 the olive and the orange tree. 



Neither does the severest cold of our winters 

 affect injuriously, in any way, the eggs of the silk- 

 worms, or the labors and products of the worms. 

 Experience has satisfactorily proved that expo- 

 sure to cold much below the freezing point, does 

 not affect the vitality of the eggs ; and if necessa- 

 rj'', it is easy to guard them from severe cold 

 weather. But there is a decided advantage in 

 iheir being kept at a low temperature through 

 winter, whether- natiu'al or artificial, as it retards 

 their hatching in spring until there is no danger of 

 frost, or of tteficiency of mulberry leaves, their 

 only suitable food. 



Thus our cold winters are cither beneficial or 

 harmless to both mulberry trees and to silk- 

 worms; and it is unnecessary to bring proofs that 

 our warm summers are belter for both, than the 

 cooler temperature of tlie summer of Europe. 



Another well known difference of climate be- 

 tween this country and western Europe, is the 

 irreater dryness of the air here; and a moist at- 

 mosphere is even more injurious to silk-worms 

 than exposure to too great a degree of cold. This 

 ground of superiority cannot be disputed ; but we 

 are not competent to estimate the amount of its 

 value.* The moisture of the air of England and 

 Ireland, more than the low temperature, has made 

 to fail the efforts there at silk-culture. 



It is the proximity of the Atlantic ocean, and 

 the prevalence of winds charged wiih its vapors, 

 that cause the greater moisture of the atmosphere 

 of the western countries of Europe. And it is 

 the more equable temperature of the ocean, com- 

 nmnicated to the winds sweeping over its surlace, 

 which serves to moderate and prevent extremes 

 both of heat and cold in those countries. For this 

 reason, as we advance eastward in Europe, from 

 the Atlantic towards Asia, though keeping on the 

 same degree of latitude, it will be found that the 

 places successively reached are more and more 

 adapted to silk-culture, just in proportion as the 

 extremes of temperature become greater. 



Arthur Young's practical observations on the 

 climate of France and Italy, and the regions of 

 diflijrent vegetable cultures, as marked in his map 

 of the former country, serve admirably to sustain 

 these views; allhouo;h he does not seem to liave 

 reasoned thus from his own observations and fiicts. 

 His division of France into the three agricultural 

 regions described above, was not made according 

 to any theory, or philosophical speculation, but by 

 his observing and noting, with the practised eye 

 of a firmer, in travelling across the kingdom re- 

 peatedly, and in various routes, the places where 

 each kind of culture began, flourished, diminished, 

 and finally ceased. Thus, the region over which 



* G. B. Smith, esq., than whom there is no better 

 authority on this subject, in his remarks in the Balti- 

 more silk convention, (published since this piece was 

 written,) attaches so much importance to the greater 

 dryness of the air of this country, that he deems that 

 alone sufficient to give to silk-culture here superior 

 profits over that of Europe. See p. 83, vol. vii, F. R. 



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