106 Transactions. — Miscellaneous. 



cargo is at the present time abnormally high, and there 

 is reason for believing that, if left alone, il would continue co 

 increase until spontaneous combustion ensued. Samples of 

 the coal taken by me have been analysed by Mr. J. C. Mingaye 

 in the departmental laboratory, with the following results : 

 From No. 2 hatch: Hygroscopic moisture, No. 1, 2-65, 

 No. 2, 2-81 ; volatile hydrocarbon, No. 1, 35-80, No. 2, 35-32 ; 

 fixed carbon. No. 1, 55-30, No. 2, 54-47 ; ash. No. 1, 6-25, 

 No. 2, 7-40; sulphur. No. 1, 0-535, No. 2, 0-453. From No. 4 

 hatch : Hygroscopic moisture, 2-45 ; volatile hydrocarbon, 

 37-55; fixed carbon, 52-30; ash, 7-70; sulphur, 0-508. It 

 may be stated, therefore, that the cai'go consists of semi-bitu- 

 minous coal of good quality, but containing large proportion 

 of dust and smalls. The coal was, I am informed, screened 

 at the pit-mouth, and its present condition is, I presume, due 

 to subsequent handling. From the investigation of eminent 

 European authorities, such as Kichters, Fayol, Lewes, and 

 others, there can be little doubt — •(!) that the principal cause 

 of spontaneous combustion in coal is the absorption of oxygen 

 by the coal ; and (2) that the most favourable conditions 

 for the self-heating of coal are a mixture of small pieces and 

 dust, an elevated temperature, a large mass or volume of coal 

 to act as a non-conducting covering, and a certain volume of 

 air. These conditions are precisely those which exist in the 

 ' Knight of St. Michael's ' cargo. The cargo was, I under- 

 stand, loaded during the abnormally hot weather which 

 prevailed at the end of January, and it is probable, therefore, 

 that it reached the hold with an initial temperature of from 

 120° to 150° Fahr. In loading from the trucks at New- 

 castle a considerable proportion of small and dust has been 

 produced by the fall and by the process of trimming ; by the 

 filling-up of the hold the volume of coal necessary to form a 

 non-conducting covering has been provided ; while just about 

 sufficient air has access to the hold to complete the necessary 

 conditions. I am of opinion, therefore, that the heating of 

 the cargo of the ship ' Knight of St. Michael ' is due, firstly, to 

 the fact that the coal contains a large proportion of ' small ' 

 and ' dust,' and, secondly, to its having been loaded during 

 abnormally hot weather. The proportion of ' small ' and 

 ' dust ' has no doubt been increased by the shifting opera- 

 tions which have taken place since the arrival of the ship 

 in Port Jackson, and I am of opinion that considerable risk 

 would be incurred if the ' Knight of St. Michael ' were 

 allowed to put to sea with her cargo in its present sttite. — 

 Edward F. Pitman, Government Geologist." 



I think it is open to doubt whether the hot weather 

 in January caused the heating of the coal in the " Knight of 

 St. Michael," as the temperature of the coal at the side 



