1872.] change of Climate on the Human Economy, 



9 



Table VIII. shows : — First, that tropical are more favourable to growth 

 in height than temperate climates ; second, that the influence of 

 both is more decided on a second than a first exposure. 



Gain 

 I in height. 



Stationary 

 in height. 



Per cent. 



Average 



gain, 

 inches. 



Per cent. 



Average 

 inches. 



6875 



0-64 







'• 46-81 



0-5 



53-I9 





1 6 9'57 



0*52 



30*43 





! 4 I '3 I 



0-29 



58-69 





23-91 



o-43 



76-09 





Exp. 



Effect of heat: 60 days in the tropics, temp. 



7 o°-82° F 



Effect of cold: 60 days in theS. Temp. Zone, 



temp. 55°-7o° F 



Effect of cold : 60 days in the N. Temp. Zone, 

 temp. 52°-7o° F 



Effect of cold : 60 days in the N. Temp. Zone, 

 temp. 32°-5o° F 



As heat thus makes the young shoot rapidly, it might be deemed 

 favourable to the bodily development ; but as the results are so different 

 from those in Table VII., they cannot be taken as a true index of the 

 healthiness of tropical climates, and must be studied with those of weight. 



An increasing weight, with either an increasing (Table IX. col. 1) or 

 even stationary height (col. 2), is a healthy sign; but if youths who 

 should be growing in weight and height remain stationary (col. 3), or 

 remain of the same height but lose weight (col. 4), or even grow in height 

 while weight does not increase (col. 5), and still more if height increases 

 while weight loses (col. 6), their physique must be deteriorating. 



Table IX., with its two columns of averages contrasting these favourable 

 and unfavourable signs, gives results similar to Table VII. ; and 

 shows -.—first, that tropic heat is unfavourable to the bodily develop- 

 ment ; second, that cold climates are favourable to it ; third, that 

 the impairing effect of a second is greater than that of a first ex- 

 posure to heat ; fourth, that each successive exposure to heat lessens 

 still further the bracing influence of cold. 



Exp. 



Effect of heat : 60 days in the tropics, \ 



temp. 7o°-82° F J 



Effect of cold : 60 days in the S. 1 



Temp. Zone, temp. 55°-70° F. ... J 

 Effect o heat : 60 days in the tropics, 1 



temp. 70°-82° F J 



Effect of cold : 60 days in the N. 1 



Temp. Zone, temp. 52 °-7o° F.... j 

 Effect of cold : 60 days in the N. 



Temp. Zone, temp. 32°-5o° F.... 



1. 



2. 



Per 

 cent. 



3. 



4. 





6. 



Per 

 cent. 



H. + 

 W.+ 



H. 



w. + 



H. H. 

 W. W. - 







H. + 

 W. 



H. + 

 W. - 



*9 



7 



54'i 



2 



7 



6 



7 



45-8 



21 



H 



95*7 



I 







1 







4-2 





° 



H 







13 





31 



978 







86- 9 | 



J 



1 





2 



13-0 



10 



33 



93'4 













I 



6-52 



