OBSERVATIONS UPON COTTON. 



409 



Table showing the lengths of the longest and shortest 

 hairs, and mean length of 20 hairs, from various samples 

 of cotton. 









Longest 



Mean 



Shortest 









fibre. 



length. 



fibre. 





d. 





in. 



in. 



in. 



Sea Island, Edisto 



26 



Dec. i860 



2'CO 



1-680 



i'35 



Sea Island 



54 



Mar. 1863 



1-95 

 i-8o 



1-501 



i"475 

 1-444 



i-io 



Queensland cotton 



Sea Island „ 



1*20 



16 



Dec. i860 



2-05 



IIO 



Egyptian „ 



9¥ to 92 



Dec. i860 



1*55 



1-252 



0-95 



Maranham ,, 









1*400 



1-220 



0-95 



Egyptian fair ,, 



22 



Mar. 1863 



1-500 



1-185 J 



0-85 



Benguela „ 



Pernambuco „ 







1-500 

 1-500 



ri77 

 1-1675 



0-85 



075 



23 



Mar. 1863 



Maranham „ 



8^ 



Dec, i860 



i'35 



1-127 



0-85 



Mobile „ ...... 



6i 



Dec. i860 



I-20 



1-035 



075 



Orleans ,, 



n 



Dec. i860 



1-25 



I -002 



0-70 



Upland ,, 



H 



Dec. i860 



I"20 



0-9925 



0-80 



Orleans (good midd.)... 



22-1 



Mar. 1863 



115 



0-970 



0-85 



Surat (fair Dhallerah)... 



i7f 



Mar. 1863 



I-I5 



0-9425 



075 



Surat (Dhallerah) 



5^ 



Dec. i860 



IIO 



0-925 



0-55 



Surat (middl. Comptah) 



15 



Mar. 1863 



1-05 



0-905 



0-70 



Strength of Cotton Hairs. — If experimenters have re- 

 coiled before the supposed difficulties of measuring the 

 individual hairs of cotton, so much the more have they 

 avoided even the mention of testing their tensile strengths ; 

 but, by the aid of the little apparatus described in a pre- 

 vious paper, I have made, in the course of my investiga- 

 tions, many hundred determinations of the tensile strength 

 of cotton hairs, and, taking into consideration the nature 

 of the fibre, with quite satisfactory results. The onh^ 

 previous account of experiments upon the strength of 

 cotton with which I am acquainted is contained in the first 

 volume of the ' Transactions of the Industrial Society of 

 Mulhouse,^ being read before that Society on the 20th 

 December, 1826, by M. Josue Heilmann. His method 

 consisted in taking threads spun from various kinds of 

 cotton, and ascertaining the weight required to break them 

 in some kind of yarn-testing apparatus, and then counting 

 by the microscope the number of hairs contained in the 



2 E 2 



