104 COAL-MINING WITH CAUSTIC LIME. 



COLOMBIA. 



which Wyoming Territory obtains $1,080,451, 

 and Colorado $1,041,250. 



5. Total number of men and boys employed, 

 3,441; of these, 1,434 are in Colorado, and 

 1,000 in Wyoming Territory. 



6. Wages paid to all classes, $1,828,401. 



7. Steam-engines used, 42 ; of these, 20 are 

 in Colorado. 



8. Value of real estate, $6,858,300 ; of this, 

 $5,448,100 are credited to Colorado. 



9. Acres of coal-land, 33,000 ; 23,592 being 

 in Colorado. 



III. Production of coal in the United States 

 for the year ending June 1, 1880, by coal-fields 

 (tons of 2,000 pounds) : 



1. BITUMINOUS : 



Appalachian field 29,842,240 



Western field (Illinois, Indiana, etc.) 8,721,101 



Michigan field 100,800 



Triassic field (Virginia and North Carolina) . . . 46,246 



Iowa and Kansas field 2,232.458 



All fields west of the one hundredth meridian. 1,477,786 



Total bituminous 42,420,581 



2. ANTHRACITE : 



Pennsylvania 28,640,819 



Ehode Island 6,176 



Total anthracite 28,646,995 



Grand total coal production 71,067,576 



Grand total of hands employed 170,585 



In this connection it may be noted that the 

 production of coal in England was, in 1855, 

 64,661,401 tons, in 1877 it was 136,179,968 

 tons, and in 1880 it was 146,818,122 tons. 

 The number of collieries in 1880 was, in Eng- 

 land, 3,880, and in the United States 3,264. 



COAL-MINING WITH CAUSTIC LIME. 

 A new method of bringing down coal, in which 

 quicklime takes the place of explosives, has 

 proved a success in English coal-mines. The 

 lime is obtained in a strongly caustic state from 

 mountain limestone. It is first ground to the 

 finest powder, and then pressed into compact 

 cakes by a pressure of forty tons. The cakes 

 are of the form of cartridges, two and a half 

 inches in diameter, with a groove along the 

 side. The hydraulic press, specially designed 

 for compressing the cartridges, can be erected 

 at a moderate cost in any colliery. The car- 

 tridges are ready for use after coming out of the 

 press, but until they are needed they must be 

 kept in air-tight boxes, to preserve them from 

 damp. The drill-holes are made with a light 

 boring-machine, and an iron tube, about half 

 an inch in diameter, is inserted in the hole 

 along its whole length. The tube is provided 

 with a groove along the outside with perfora- 

 tions. A bag of calico covers the perforations 

 and one end of the tube, and has a tap fitted 

 on at the other end. The cartridges are lightly 

 rammed, so as to insure their filling the bore- 

 hole. They are inclosed with tamping in the 

 same manner as a gunpowder-charge. The 

 charge is then ready for blasting. This is ac- 

 complished by connecting the tap at the end 

 of the iron pipe with a small force-pump by 

 means of a flexible tube, and forcing in a quan- 

 tity of water equal in bulk to the quantity of 



lime in the tube. The water is driven to the 

 lower end of the shot-hole through the tube, 

 and escapes along the groove through the per- 

 forations and the calico, saturating the lime 

 and driving out the air. The tap is closed, to 

 prevent the escape of the steam generated by 

 the action of the water on the lime. There is 

 an interval after the introduction of the water 

 before the steam attains a high pressure, so 

 that all danger can be avoided. The action of 

 the steam cracks the coal away from the roof. 

 The sprags are left in under the coal, so as to 

 allow the fissures to extend as far as possible. 

 In many cases the coal is broken away for a 

 distance of several inches beyond the end of 

 the drilled holes. The expansive force of the 

 steam generated by the usual charge of seven 

 cartridges is about 2,850 pounds. The expansion 

 of the lime takes place subsequently. Its ef- 

 fect may be measured by comparing the bulk 

 of a quantity of lime equal to that used in the 

 cartridges before and after slaking. The action 

 is over in from ten to fifteen minutes. When 

 the sprags, or props, are then removed, the 

 coal falls from the roof in large masses, leaving 

 a clean surface. The waste in dust and small 

 coal is much less than when powder is used for 

 blasting, being only about six per cent. For 

 economy, thoroughness, avoidance of smoke, 

 etc., the new process offers many advantages 

 over gunpowder-blasting ; but its greatest merit 

 consists in averting the danger of explosions 

 from the ignition of gas by the blast. 



COLOMBIA (EsTAcos UNIDOS DE COLOM- 

 BIA). For statistics relating to area, territorial 

 division, population, etc., see " Annual Cyclo- 

 pedia " for 1877. The Executive of the confed- 

 eracy, President F. Zaldua, inaugurated April 

 1, 1882, died later in the year, and the Federal 

 Congress at Bogota appointed Messrs. Otalora, 

 Aldana, and Hurtado to exercise jointly the 

 Federal executive power as " Designados " to 

 the end of the presidential term. The Cabinet 

 was composed of the following Ministers : Sec- 

 retary of State and head of the War Depart- 

 ment, Sefior B. Noguera; Public Instruction, 

 Seftor J. M. Campas; Interior, Sefior J. de J. 

 Alirar ; Finance, Sefior M. Samper ; Treasury, 

 Sefior N. Borrero; Foreign Affairs, Sefior J. 

 M. Suijano Wallis; and Public Works and Post- 

 Offices, Sefior F. F. Paul. 



The chief magistrates of the nine States were 

 as follow : 



Antioquia, Sefior Lucien Restrepo ; Bolivar, 

 Sefior Benjamin Noguera ; Boyacd, Sefior Aris- 

 tides Calderon ; Cauca, Sefior Ezequiel Hurta- 

 do ; Cundinamarca, Sefior Daniel Aldana ; Mag- 

 dalena, Sefior Jose Maria Campo Serrano ; Pan- 

 amd, Sefior Rafael Nufiez; Santander, Sefior 

 Solon Wilches; Tolima, Sefior Marcelo Bar- 

 rios. Each of the foregoing functionaries has 

 the title of president, except those of Cundina- 

 marca and Tolima, who are styled governors. 



The United States Minister Plenipotentiary 

 to Colombia is General Manney (accredited 

 September 21, 1881), and the United States 



