FRAGMENTS OF SCIENCE. 



427 



E. D. Bell and appeared in Nature for 

 March 23d. The table was made for 

 the purpose of demonstrating a con- 

 stant relation (in length) between these 

 two periods of life, which the author 

 expresses in the following formula, in 

 which f. t. I. = full term of life, and 

 p. m. the time required to arrive at 

 maturity : 



f. t. 1. 



10.5 (p. m.) 



, or 10.5 X (p m.) f 



V(p. m.) 



and which seems to be fairly well borne 

 out by the table: 



The Manufacture of Firecrackers 

 in China.— There were exported from 

 China during the year ending June 30, 

 1897, 26,705,733 pounds of firecrackers, 

 all from the province of Kwantung. 

 The exports, however, represent only a 

 small portion of the number manufac- 

 tured, as the use of the cracker is uni- 

 versal all over China. They are used 

 at weddings, births, funerals, at fes- 

 tivals, religious and civil, and in fact 

 on all occasions out of the ordinary 

 routine. The United States consul gen- 

 eral at Shanghai gives the following, ac- 

 count of the industry: There are no 

 large factories; the crackers are made 

 in small houses and in the shops where 

 they are sold. In making them only 



the cheapest kind of straw paper is used 

 for the body of the cracker. A little 

 finer paper is used for the wrapper. A 

 piece of straw paper, nine by thirty 

 inches, will make twenty-one crackers 

 an inch and a half long and a quarter 

 inch in diameter. The powder is also 

 of the cheapest grade, and is made in 

 the locality where used. It costs about 

 six cents per pound. For the fuse a 

 paper (called "leather" in Shanghai) is 

 used, which is imported from Japan, 

 and is made from the inner lining of 

 the bamboo. In other places a fine rice 

 paper is used, generally stiffened slight- 

 ly with buckwheat-flour paste, which 

 the Chinese say adds to its inflammabil- 

 ity. A strip of this paper one third 

 of an inch wide by fourteen inches (a 

 Chinese foot) long is laid on a table, 

 and a very little powder put down the 

 middle of it with a hollow bamboo stick. 

 A quick twist of the paper makes the 

 fuse ready for use. The straw paper is 

 first rolled by hand around an iron 

 rod, which varies in size according to 

 the size of cracker to be made. To 

 complete the rolling a rude machine is 

 used. This consists of two uprights 

 supporting an axis from which is sus- 

 pended, by two arms, a heavy piece of 

 wood, slightly convex on the lower side. 

 There is just room between this swing- 

 ing block and top of the table to place 

 the cracker. As each layer of paper is 

 put on by hand, the cracker is placed 

 on the table and the suspended weight 

 is drawn over the roll, thus tightening 

 it until no more can be passed under 

 the weight. For the smallest " whip " 

 crackers, the workman uses for com- 

 pression, instead of this machine, a 

 heavy piece of wood fitted with a handle 

 like that of a carpenter's plane. In fill- 

 ing crackers, two hundred to three hun- 

 dred are tightly tied together in a 

 bunch; red clay is spread over the end 

 of the bunch, and forced into the end 

 of each cracker with a punch. While 

 the clay is being treated a little water 

 is sprayed on it, which makes it pack 

 closer. The powder is poured in at the 

 other end of the cracker. With the 

 aid of an awl the edge of the paper is 

 turned in at the upper end of the 

 cracker, and the fuse is inserted throtigh 

 this. The long ends of the fuses are 

 braided together in such a way that 

 the crackers lie in two parallel rows. 



