52 FIELD MUSEUM OF NATURAL HISTORY 
represents a huge producer in the MacDonald field. A piece of 
sandstone from which the oil is obtained is placed at the bottom. 
Upon the wall a chart shows a geological section between Olean, 
New York, and Fort Wayne, Indiana. The position of the oil- 
bearing sands in these and the comparatively undisturbed con- 
dition of the strata are significant of conditions favorable to the 
storage of vast quantities of petroleum and gas. A similar 
chart gives a geological section between Olean, New York, and 
Massillon, Ohio. 
Specimens of oil-bearing rocks from many localities include 
sands, gravels, porous sandstones, and limestones. 
The minerals and fossils of the oil-bearing strata of Penn- 
sylvania and Ohio are represented by a varied series of specimens. 
A large bottle represents one barrel of petroleum, and the 
products of such a barrel of petroleum are arranged according 
to the order in which they are obtained. These are (i) naptha, 
(2) burning oils, and (3) residuum of petroleum tar. The pro- 
cesses and products of further distillation of the latter will also 
be seen. A large model of a modern oil refinery permits the 
tracing of all stages of the manufacture of illuminating oils from 
petroleum. Above this model will be seen one of the refineries 
built in Cleveland, Ohio, in 1863. 
Much of the space in this hall is occupied by various finished 
products ready for sale, these being chiefly illuminating and lubri- 
cating oils with, however, a variety of other useful articles. 
These products are classified into groups which include: 
1. Cylinder oils of many grades. These are the heavier, 
more sluggish, lubricating oils. 
2. Special grades of lubricating oils. These include spindle, 
sewing machine, screw-cutting and engine oils. They are light- 
bodied and quick-feeding as compared with the cylinder oils. 
3. General heavy oils, including miners’ oil, leather oil, and 
various engine oils. 
4. A collection of the by-products of petroleum, including 
paraffin wax, crude, semi-refined and refined, with illustrations 
of its use for candles, matches, tapers, etc. ; axle grease, lantern 
oil, harness oil, “miners’ sunshine,” for miners’ lamps; vaseline 
products, such as cerates, pomades, soap and face paints. 
5. Special grades of illuminating oils. These oils are 
designed to give the best light obtainable from kerosene. 
6. High test illuminating oils. 
