228 BULLETIN 42, UNITED STATES NATIONAL MUSEUM. 



(9) Squib box, used for carrying fuses or squibs in the mines for liriug the shots. 

 (59204.) 



(10) Steel wedge, used in breaking up the coal. (59196.) 



(11) Sledge, form used iu this mine for driving the wedge into the coal. (59151.) 



(12) Scoop shovel, used inside of mine for loading mine wagons. (59150.) 



(li}) Miner's ticket, placed upon each car loaded by a given miner in order to get 

 proper credit for his work. (59201.) 



(14) Ticket hook, to be fastened to the bottom of the coal car, and used to hold 

 the ticket of the miner getting out the load. (59202.) 



(15) Sprag, new, oak, cigar shaped, 18 by 2 inches; used instead of a break by 

 thrusting it between the spokes of the mine wagon wheels. (59154.) 



(16) Sprag, old, cigar shaped, 13 by 2 inches; used instead of a brake by thrusting 

 it between the spokes of the mine wagon wheels. (59155.) 



(17) Mine railway spike, form used for the mul^ road or tramway. (59200.) 



(18) Hand ax, a short-handled ax used for making cap pieces. (591.57.) 



(19) Cap piece, wedge of wood driven in between the prop and roof, in breast of 

 mine, to fasten the prop. (59158.) 



SEMI-BITUMINOUS COAL. 



Composition : 68 to 77 ])er ceut. fixed carbon, 1 L to 17 per cent, vola- 

 tile matter, and 7 to 13 per ceut. impuritieis, including water. 



There is little in the physical character to distinguish the semi-bitu- 

 minous from the true bituminous, except by an expert. On burning 

 they yield a larger and more permanent flame than the semi-anthracite, 

 but a shorter flame than the bituminous. Considering that they gradu- 

 ate insensibly into the bituminous, it is to be expected that they would 

 not difler materially in physical characters. They are liable to be found 

 in any bituminous field, and have been largely mined in most of our 

 bituminous areas. 



The semi-bituminous coals are illustrated by three collections. 



From the Long Valley Mine, Barclay, Bradford County, Pennsyl- 

 vania, are shown a section of the vein, with a few accessories, and three 

 characteristic photographs. 



The coal is of the following composition : 



Per cent. 



Water 1.990 



Volatile matter 18. 530 



Fixed carbon 67. 423 



Sulphur 1.742 



Ash 10.315 



100. 000 

 Phosphorous 0, 0061 



(1) Top slate. (59070.) 



(2) Coal, top, from south gangway. (59068.) 



(3) Coal, top, from main west gangway. (59069.) 



(4) Coal, bottom. (59067.) 



(5) Fire clay, bottom. (.59071.) 



(6) Oak sprag, used instead of a brake by thrusting it between the spokes of the 

 mine wagon wheels, both in and outside of mine. (59072.) 



