110 CEMENTS, LIMES, AND PLASTERS. 



lime may vary from 300 to 500 Ibs. These limits have been assumed 

 in the estimate below, while the cost of coal has been taken as varying 

 from $2 to $3 per ton. These prices are fairly representative for 

 most of the lime-plants of the country. 



Labor costs are estimated with a rather liberal maximum limit. 



The final results of these calculations are shown below. 



TOTAL COST OF LIME-MANUFACTURE PER TON. 



Interest on cost of plant and quarry $0 . 05 to SO . 20 



Taxes, minor supplies, etc 0. 10 " 0.25 



Cost of quarrying two tons of limestone. ... . 50 ' ' . 90 



Cost of fuel for burning . 30 " . 75 



Cost of labor, exclusive of quarrymen . 25 ' ' . 80 



Total cost per ton of burned lime, in 



bulk (2000 Ibs.) $1 .20 " $2.90 



This corresponds to costs of 4.2 to 10.15 cents per bushel of 70 Ibs. 

 The minimum estimate represents what might be attained by a good 

 modern plant, run steadily and under exceptionally favorable conditions 

 as regards quarrying, fuel, and labor. The maximum estimate could 

 easily be exceeded by the small or unsteadily operated plants. The 

 average cost throughout the entire country is probably in the neigh- 

 borhood of 6 to 8 cents per bushel. 



General estimates of costs of lime-manufacture by the use of Hoff- 

 man kilns will be found on pages 106 and 108. 



Actual costs of lime-manfuacture in 1900. In connection with the 

 above estimates of cost it is of interest to compare certain statistics 

 collected by the Census Bureau in 1900 and published in vol. 7, Reports 

 Twelfth Census, pp. 274-277. The tables on the pages cited give total 

 costs of various elements in lime- and cement-manufacture in all the 

 states during 1900. As the figures for lime, natural cement, and Port- 

 land cement are tabulated together, most of the tables are of little 

 value for our present purpose. In the ten states considered below, 

 however, no natural- or Portland-cement plants were in operation during 

 1900, so that the statistics for these states must necessarily apply only 

 to the lime industry. The data relating to these ten states have ac- 

 cordingly been slightly rearranged and are shown in the following table. 



As the total quantities of lime produced are not stated, it is impos- 

 sible to reduce the total costs given in the table to costs per ton 

 or bushel of product. A simple calculation, however, enables us to 

 reduce them to percentages of the total cost, so that the relative im- 

 portance of the various elements making up this total can be readily 



