504 ANNUAL KECORD OF SCIENCE AND INDUSTRY. 



cient supply of the tree squirrels, such as the red, the gray, 

 the fox squirrel, etc., throughout the various parts of the 

 country, to meet a very large demand. Chicago Field. 



NUMBERING SILK THREAD AND FABRICS. 



The system of numbering yarns by giving the number of 

 meters in a gramme, agreed upon by the International Con- 

 gress assembled at Vienna during the Exposition, is not sat- 

 isfactory for silk threads, which are not, properly speaking, 

 spun, but result rather from the simple combination of threads 

 already formed. While the numbers of spun yarn may there- 

 fore be accurately expressed by the differences in length of a 

 given weight of yarn, unvarying practice indicates that, for 

 silk, it is preferable to employ the variations in weight of a 

 given length of yarn, although the numbering on this plan 

 begins with the finest instead of with the coarsest threads, as 

 in the former case. Besides, the numbers for silk on the new 

 plan would be inconveniently large. The original basis for 

 the numeration of silk w^as the number of deniers (twenty- 

 fourths of the old French pound) in 9600 ells; and afterward, 

 on account of convenience and economy of time, the number 

 of grains (twenty-fourths of a denier) in 400 ells, the name 

 denier being retained ; but it was found to vary greatly in 

 different countries on account of the difference in the value 

 of the o-rain; and even after chanoes in 1856 in France and 

 Italy, the basis in France was 500 meters and 0.05311 

 gramme; in Italy and Switzerland, 450 meters and 0.050 

 gramme; and in Germany 476 meters and 0.05336 gramme. 

 A basis of 500 meters and one half of a decigramme, sug- 

 gested by the Chamber of Commerce of Crefield in 1874, 

 was presented to the Congress at Brussels. While the ex- 

 ceptional character of silk in a system of numbering was 

 recognized by that body, a desire w^as manifested to render 

 the metrical character of its basis more apparent, and to give 

 it a simpler relation to that of the others by making the 

 units 1000 meters and one decigramme, in which case No. 1 

 of silk would correspond to 100,000, and No. 20 to 1000 of 

 the other system. To this it was objected that, however de- 

 sirable such a basis might seem theoretically, it w^as question- 

 able on practicable grounds ; since, from the nature of silk, 

 it is impossible to produce threads of as great uniformity as 



