REPORT OF THE DIRECTOR AND STATE GEOLOGIST 1903 145 



village, so that the entire equipment consists of one Blake 

 crusher, one nipper, eight burstone mills, four kettles, two 

 shaking screens, one single mixer, one triple mixer and one sand 

 drier. The power for running the machinery is furnished by a 250 

 horse power cross compound engine. 



At the west end of the mill is a large rock shed, where in 

 slack times the surplus rock is stored. When the mill is run- 

 ning to its full capacity, it takes the full output of the mine to 

 keep it running. The plaster rock for this mill is obtained from 

 two mines about a half a mile north of the mill. They are 

 entered by a vertical shaft, and the rock is raised from the mines 

 by two 50 horse power hoisting engines. Howell twist drills, 

 run by compressed air, are used, and an automatic air compres- 

 sor at each mine furnishes the requisite power. The blasting 

 is all done with black powder. At the east end of the mill is the 

 sand bed where the sand for the Big Four wall plaster is stored 

 and dnied. This sand is brought from the pit, which is about a 

 quarter of a mile northeast of the mill, ^by a tramway, and after it 

 has been dried and screened, it is put in a storage bin, from 

 which it is taken, as required, to the mixers. As noted in the 

 statement of the equipment, there are two mixers, one single and 

 the other triple. The first of these is used in mixing the hard 

 wall plaster which is sold under the name of Ivory wall plaster, 

 while the triple mixer is used in the mixing of the sand and 

 fiber plaster known to the trade as the Big Four toall plaster. 



On the third floor of the mill is a testing laboratory for test- 

 ing the strength of the plaster. Samples of every shipment are 

 tested, and the record, as well as a duplicafte sample of the 

 material, is kept, so that the company is able not only to know 

 that satisfactory material is being shipped, but, in case of com- 

 plaint, to prove the quality of the material when shipped. The 

 results of the tests for tensile strength made in the laboratory 

 are possibly somewhat lower than they should be, because there 

 is a great deal of vibration in this part of the mill, which has a 

 tendency to cause the briquets to break sooner than they other- 

 wise would. 



