282 TEMPEKATTJRE TO WHICH PLANTS 



XXXIV. — Observations upon the Temperature to wliich Plants 

 are naturally exposed in Neiv Holland. By the Vice -Secre- 

 tary. 



It is so unusual to find in books of travels any such accurately 

 detailed account of the vegetation observed, and of the climate 

 which influences it, as can be safely turned to profit by 

 gardeners, that I gladly avail myself of an opportunity of placing 

 before horticulturists a series of very interesting and unexpected 

 facts relating to the climate of New Holland, whence so many 

 of the most valuable plants in cultivation have been obtained. 

 For these facts we are indebted to the zeal and intelligence of 

 Lieut. -Col. Sir Thomas Mitchell, the Surveyor-General of New 

 South Wales. That distinguished officer, in his last journey 

 from Sydney northwards, in search of a route to the Gulf of 

 Carpentaria, spent a year in traversing lO:^^ degrees of latitude, 

 backwards and forwards. He quitted Sydney in the midst of 

 summer, December 15, reached 21^° S. lat., his most northern 

 latitude, on the 11th of August, when, turning his face to 

 the southward, he arrived again in Sydney by the end of the 

 year ; a complete season having thus been occupied in the ex- 

 pedition. 



During this period not only were observations of the weather 

 taken four or five times a day, whenever the difficulties of the 

 journey would permit, but the plants wliich were preserved by 

 the naturalist attached to the expedition were also regularly 

 dated, so that upon his visit to England Sir Thomas Mitchell's 

 plants were capable of tolerably accurate comparison with his 

 meteorological journal. The observations themselves are dispersed 

 throuffh his valuable Narrative ;* but not having' been condensed 

 there with a view to establishmg any general facts, I have 

 thought it advisable to extract such parts as have a bearing 

 upon horticulture, adding some further information derived 

 from an unpublished Meteorological Journal, with which Sir 

 Thomas has favoured me. To avoid unnecessary length, I have 

 thrown together the observations in such a way as to make each 

 set correspond with one degree of latitude nearly. The figures 

 follow, day by day, under their respective heads, by which means 

 the daily variations can be judged of as accurately as is needed for 

 the establishment of horticultural principles. And, finally, a few 



* Journal of an Expedition into the Interior of Tropical Australia, in 

 search of a Route from Sydney to tlie Gulf of Carpentaria. By Lieut.-Col. 

 Sir T. L. Mitchell, Kt., D.C.L. 8vo. Longmans, 1848. 



