176 LOWER PENINSULA. 



the pumping rods or jarring the tubing loose at the joints, causing 

 leakage. 



The capacity of salt wells varies in different localities, from 12 

 to 20 gallons per minute — the size of the well and the quan- 

 tity and porosity of the sand rock having much to do in increasing 

 the amount. A good well will fill a cistern 20x30x6 feet in about 

 20 hours. A salt well in Saginaw City owned by Pierson, Wright 

 & Co. produced enough brine during a manufacturing season of 

 eight months to make over 26,000 barrels of salt. At East Tawas, 

 the wells, 3|- inches in diameter, fill a cistern of the above size in 

 about twelve hours. At Port Austin, the well fills a cistern in 

 seventeen hours. 



TESTING THE STRENGTH OF BRINES BY SALINOMETER, 

 WITH COMPARATIVE TABLES. 



The following table is extracted from Alexander Winchell's Re- 

 port on the Geology of Michigan, published in 1861 ; it has been 

 thought advisable to reprint it at length as a guide to our salt man- 

 ufacturers. 



" Pure water dissolves, at ordinary temperature, a little over one 

 third its weight of salt, or from thirty-five to thirty-six hundredths. 

 The amount varies somewhat with the temperature, and the results 

 of different experiments are, moreover, not perfectly accordant ; 

 but from the most accurate observations, it appears that 100 parts 

 by weight of pure saturated brine, at temperatures from 32° to 

 70° Fahr., contain from 26.3 to 26.7 parts of salt. Some earlier 

 determination, however, gave but 25.7 parts, and upon this figure 

 the table was calculated. 



"The specific gravity of a saturated brine at 60° Fahr. is 1.205 

 pure water, being i.ooo. The salinometer employed in many salt 

 works for fixing the value of brine is an areometer with an arbitrary 

 scale divided into 100 parts. The density of water on this scale is 

 represented by 0° and that of saturated brine by 100°. Each de- 

 gree of the salinometer, therefore, corresponds very nearly to one 

 quarter of one per cent of salt. In the following table, the true 

 specific gravity, with the corresponding degree of the salinometer, 

 and of the hydrometer of Baume, is given in the first three 

 columns. The succeeding columns give the percentage of salt in 



