496 
LOWER OOLITIC ROCKS OF ENGLAND : 
bulk the material acted upon. The insoluble residue under the microscope 
is seen to be made up of several constituents. The principal of these are 
rounded or sub-angular grains of pure white quartz, varying in diameter 
from T Q to -5-^0 of an inch, and rounded, siliceous, oolitic concretions of a 
pale-green colour, from -^ to T p of an inch in diameter. Besides these, 
we frequently find in some specimens a number of scales of mica, and in 
others black fragments, which dipappear on the ignition of the mass, and 
are thereby recognised as carbonaceous matter. The quantity of the 
latter substance is in some samples very considerable. Some of these 
facts concerning this insoluble portion of the Northamptonshire ore have 
already been noticed by Dr. Percy."* (See p. 12.) 
The following are the localities and names of the present or former 
workings in the Northampton Ironstonef : 
Oxfordshire. 
-J- Steeple Aston. (See p. 163.) 
Leicestershire, 
-f-Neville Holt, Medbourn, N.E. I +Waltham-on-the-Wolds. 
of Market Harborough. 
Lincolnshire. 
Greetwell, Lincoln. -J- Canwick, Coleby, andWaddiug- 
ton. 
Northamptonshire. 
Great Addington, S.W. of 
Thrapston. 
Barton Seagrave, S.E. of Ket- 
tering. 
Blis worth. 
Brixworth, N. of Northamp- 
ton. 
Burton Latimer, S.E. of Ket- 
tering. 
Chelveston, near Higham 
Ferrers, 
-f- Cogenhoe, E. of Northampton. 
Corby, N. of Kettering. 
Cranford St. John, E. of Ket- 
tering. 
Cransley. S.W. of Kettering. 
-j- Culworth, N. of Brackley. 
Desborough, N. of Rothwell. 
Ditchford, Irthlingborough, 
E. of Wellingborough. 
Duston, W. of Northampton. 
Easton Hill and Burleigh 
Park, S. of Stamford. 
Easton Neston and Shuttle- 
hanger, N.E. of Towcester. 
Finedon (Thingdon), N.E. of 
Wellingborough. 
Gayton, N.W. of Blisworth. 
Glendon, N. of Kettering. 
Gretton, N. of Kettering. 
Harrowden Road, Great Har- 
rowden, N. of Welling- 
borough. 
Heyford, W. of Nether Hey 
ford, near Weedon Beck. 
Hunsbury Hill, S.W. of 
Northampton . 
Irchester. 
Irfchlingborough, Welling- 
borough. 
Islip and Slipton, W. of 
Thrapston. 
Lamport, S.W. of Rothwell. 
Loddington, W. of Kettering. 
Newbridge, Twywell, W. of 
Thrapston. 
Eingstead, S. of Thrapston. 
Rnshton, N. of Kettering. 
Spratton, N. of Northampton. 
-j- Stowe-nine-Churches, W. of 
Northampton. 
Warren Hill, N.W. of Ket- 
tering. 
Wellingborough. 
Wollaston, S. of 'Welling- 
borough. 
Woodford, W. of Thrapston. 
Eiitlandshire. 
Cottesmore, N.E. of Oakham. | -j-Manton, S. of Oakham. 
* Judd, Geol. Bntland, pp. 116, 121; See also Dick, Iron-ores of Great Britain, 
Part I., p. 95. 
f The localities marked + , and perhaps some others, are no longer worked for 
ironstone. 
