September 20, 1918. THE COLLIERY GUARDIAN. 599 __________ _______ _______________________ ______ ________________________________________________________________________________ Table G-.—Summary. Block No. Col. 1. Planimeter reading. Col. 2. Dip. Col. 3. Area factor. Col. 4. Inclined area. Col. 5. Stope width. Col 6. Ton factor. Col. 7. Tons. Col. 8. Value dwts. Col. 9. Contents (Tons x value). Col. 10. 1 2 3,875 1,047 38 32 22'0315 21'4718 85,372 21,434 4-8 48 7’34386 6'82392 28,457 7,141 8-3 7-7 236,193 55,009 106,806 48 35,601 8'2 291,202 This amount is equivalent to, roughly 31 per cent, on the capital invested. It will now be necessary to find the present value of a £1 share on which a divi- dend of 31 per cent, may be expected for a period of nine years, it being assumed that the mine will be able to maintain its full crushing until the end of its life, which, generally, is not the case, since near the time of closing down the ore available is not sufficient to allow of the full crushing capacity being maintained, and hence the life is somewhat extended and the annual profit during that period reduced. A ■ ■ V5' Al y 11 * fl FaxiZt x Dvkt / II 01 1 /S //oarje Dettft.. II Fig. 6.—Reef with Dyke Dislocation. .Mi '' II ■ .A'A. A ■ m—. ___________...... Fig. 7.—Reef with Dyke Dislocation. 1,500,000 tons having a.value of 7 dwt. There are, say, 200 claims undeveloped containing 25,000 tons per claim. It is assumed from the results obtained in the developed portion of the mine that 5 per cent, of the remaining area will be taken up by dykes, and that 80 per cent, of the ore will be payable: — Tons. 200 claims at 25,000 tons per claim... = 5,000,000 Less 5 per cent, for dykes .......... 250,000 4,750,000 Less 20 per cent, unpayable....... 950,000 Probable payable ore .............. = 3,800,000 Existing ore reserves .............. 1,500,000 Total ore to be mined............... 5,300,000.... Mining at the rate of 600,000 tons per annum, the life of the mine may be taken at, say, nine years. The working costs are tafffen at 18s. Id., and it is under- stood that development rock will not be crushed. The approximate annual profit can now be obtained, as follows : — ,,, Value Gold Tons- dwts.’ contents. dwts. Mining ................ 600,000 at 7’00 will yield 4,200,000 Less Sorting at 20% .... 120,000 at 0’5 ,, ,, 60,000 Tons Milled .......... 480,000 at 8’625 ,, ,, 4,140,000 Less allowance for Sampler’s error 95% ... 480,000 3,933,000 Reduction Works—Ex- traction of 95% ...... 480,000 3,736,350 Less Costs.............. 480,000 4’3 2,064,000 Profit in dwts..................................... 1,672,350 Less 10% Profit Tax .............................. 167,235 Fig. 8.—Narrow Stope worked by Hand Labour. Profit.... 1,505,115 = <£316,074 Table H.—Block No. 1. Locality. Length. Reef Channel. Length x Reef Channel- Reef Channel value. Length x R^ef Channel x Reef Channel value. 7th Level, No. 1 Winze West 175 14-5 2,537 24’1 61,142 7th Level West, Boxhole No. 11 35 12’0 420 15'0 6,300 „ „ ., ,, „ 12 35 24’0 840 16’2 13,608 " " ,, „ „ 13 35 17’0 595 32 T 19,100 ,, „ „ 14 35 29'0 1,015 17-2 17458 ,, „ „ „ „ 15 35 32'0 1,120 12'5 14,000 .. „ „ 16 35 250 875 14'7 12 863 ,, „ „ „ 17 35 12'0 420 21'5 9,030 35 21’0 735 16’5 12,128 „ „ „ „ ,, 19 35 19-0 665 11-5 7,648 ,. ., ,. „ „ 20 35 360 1,260 16-1 20,286 225 16’5 3,713 24’1 89,483 8th Level West, Boxhole No. 12 35 16'0 560 11-3 6',328 „ „ „ „ „ 13 35 16'0 560 16-4 9,184 ,, ,, „ „ ,, 14 35 6’0 210 73'2 15,372 „ „ ,, „ ,, 15 35 12-0 420 34 6 14,532 „ „ „ „ „ 16 35 18'0 630 24'0 15,120 „ ,, ,, „ 17 35 25'0 875 29-1 25,463 ,. ,, 18 35 27'0 945 10T 9,544 19 35 160 560 27’2 15,232 ”, „ ”, 20 35 9'0 315 27'7 8'726 „ „ „ „ „ 21 35 16’0 560 17-0 9>20 1,100 18’0 19,830 20’8 412,067 48" at 8’3 Average Stope Width and Value 48'0 52'800 7-8 Should it be possible to exhaust the ore reserves by the end of the ninth year, the present value of the share can be found without difficulty. In this calculation provision must be made for the redemption of the capital invested over the period of nine years, and also for interest on the money over that period. For this purpose interest at the rate of 3 per cent, may be allowed on the redemption fund and on the money invested—that is, profitable or remunerative interest at the rate of 10 per cent. In a paper of this description space will not allow of this subject being fully treated, but the following short explanation may suffice to make the various steps clear. The sum which an annuity of £1 will amount to in n years is expressed by the following formula : — R» - I r where R = (1 -f- r) and r — rate of interest. Consequently the quantity which will amount to £1 in n years will be represented by the formula: — Table I.—Block No. 2. Locality. Length. 35 225 35 35 35 35 Reef Channel. Length x Reef Channel. Reef Channel Value. Length x Reef Channel x Reef Channel Value 7th Level West. Boxhole No. 22 7th Level No. 2 Winze West 8th Level West, Boxhole No. 23 „ „ „ „ „ 24 „ >■ „ „ „ 25 „ „ ■> „ „ 26 Totals and Averages Averages, Stope, Width and Value 22 0 16’5 16-0 6-0 14-0 19'0 770 3,713 560 210 490 665 15’2 24-1 11- 2 43'7 12- 7 27-2 11,704 89,483 6,272 9,177 6,223 18,088 400 16’0 48'0 6,408 19,200 22'0 7-3 140,947 48" at 7’7 Now, this is equal to £1 ; therefore