880 
MANGANESE DEPOSITS OF INDIA : DESCRIPTIVE. [PaRT IV : 
in the Kamthi Lady Pit the actual thicloiess of the ore-bed is at least 
47 feet. Hence we see that the ore- band is of fairly iiniform thickness, 
namely about 45 feet. 
Although some good ore has been, and doubtless still can be, 
Nature and (juality obtained from the various pits at the Chargaon end of 
of theorem. the deposit, yet the merchantable ores lie cliieflv 
in the western portions, where practically the whole length of the 
deposit for the last half mile is worth working. In fact, m some places 
in the original outcrop workings, such as the parts on the top of Mansar 
Hill tapped by the aerial ropeway, and the part tapped by No. 1 Incline 
South, practically the whole thickness of the deposit seemed to consist 
of merchantable ore. Now that the deposit has beoi quarried to a 
considerable depth below the original outcrop it is found that a much 
larger proportion of the bed has to be rejected than was expected. Thus, 
in December 1906, I found masses of yellow spessartite-rock, and some of 
rhodonite-rock, both partly changed to manganese-ore, included in 
the ore-body at points where the original outcrop had indicated 
manganese-ore only. The following figures showing the actual 
proportion of cleaned ore obtained in quarrying the ore-bed, were supplied 
by Mr. W. Whyte, manager of the Mansar mine:— 
March, 1906. 
April, 1900. 
May, 1900. 
Cleaned ore . . . . . . 
Waste (smalls), consisting of ore, quartzite, etc. 
Bad ore (large pieces) ..... 
cu. ft. 
18,000 
1 1 SOO 
17,500 
cu. ft. 
18,500 
13,900 
27,000 
cu. ft. 
19,400 
11,700 
24,400 
Total 
47,900 
59.400 
55, .500 
Proportion of cleaned ore to total exc.Tvated 
.38-8% 
31-2% 
.34-9% 
Since the smalls will pack much closer than the large fragments of ore, 
both cleaned and rejected, they wou;d really occupy a somewhat larger 
volume than shown above if they were packed with the same proportion 
of air space between the fragments. Consequently the proportion cf 
cleaned ore to total excavated must be somewhat smaller than sho\vn 
above and might fairly be taken as averaging .30 per cent. 
This ore is very similar to that of Kandri, being finely crystalline, both 
hard and soft, and to a large extent composed of braunite. The difference 
between the hard and soft ores seems to be that in the hard ores the 
braimite granules are more firmly cemented by the psilomelane matrix 
than m the soft varieties ; moreover, to judge from the analyses of 
Kandri ores Nos. 994 and 995 (pp. 869-70), the harder ore contains a 
larger proportion of psilomelane to act as cement to the braunite, 
One piece of ore often consists of streaks of the two varieties. 
