no Salt Wells and Springa of Injlammahlc Gas in China. 



nidit two other men takes their place. When three inches have 

 been bored, the steel head is withdrawn, by means of a pulley, 

 with all the substances with which its upper concavity is loaded. 

 By this mode of boring, there are obtained wells which are per- 

 fectly vertical, and whose lower surface is highly polished. Beds, 

 of sand, coal, &c., are frequently met with. The operation then 

 becomes more difficult, and is sometimes entirely frustrated, for 

 these substances no longer offering an equal resistance, it hap- 

 pens that the well loses it verticality, but these cases are of rare 

 occurrence. At other times the iron ring which bears the steel 

 head breaks. When this accident happens at a certain depth, 

 the Chinese know no other means of remedying it than to em- 

 ploy a second steel head to break the first, an operation which 

 may take several months. When the rock is good, an advance 

 of nearly two feet is made in twenty-four hours; so that it takes 

 about three years to dig a well. 



The apparatus for drawing the water is equally simple with 

 that which is employed for boring. A bamboo tube, twenty- 

 four feet long, at the end of which is a valve, is let down into 

 the well. When it has reached the bottom, a workman pulls 

 at the cord which sustains it, giving it strong jerks ; each jerk 

 opens the valve, and fills the tube with water. It is then drawn 

 out by means of a kind of vertical capstan, or large windle, 

 fifteen or sixteen feet in diameter, which is put in motion by 

 two, three, or four buffaloes or oxen, and upon which the cord 

 is rolled up. 



The water of these wells yields by evaporation a fifth, and 

 sometimes a fourth of salt. This salt is very sharp, and con- 

 tains much nitre.* For distillation there are employed large cast 

 iron cisterns, five feet in diameter by only four inches in depth. 

 The metal is at least an inch thick, and at most three. The 

 mass of salt, which has the form of the cistern, weighs upwards 

 of two hundred pounds, and is very hard. It is broken into 

 three or four pieces, to be disposed of in commerce. 



Now, what is very extraordinary is, that these saline wells are 

 frequently at the same time wells of inflammable gas. If, ac- 

 cording to M. Imbert, a torch be presented to the orifice of a 



• We suspect there is here a mistake, nitre being a compound foreign to 

 salt springs. 



