4S l-ll'.LD MUSEUM OF NATURAL HISTORY 
the visitor will find illustrated: (1) The natural history of 
petroleum; (2) its manufactured products, and (3) the uses or 
applications of these. 
The specimens of crude petroleum are arranged to show 
gradations of color, this being seen to vary from black, through 
shades of dark green and brown to amber, the greenish-brown 
being most common. Even oils of the same color, however, 
may differ notabh' in specitic gravity and composition. 
Tubes filled with drillings from the successive strata passed 
through in search for oil, illustrate the material through which 
oil wells are drilled in the Pennsylvania oil fields. One of these 
represents a huge producer in the MacDonald field. Both these 
and other specimens of oil-bearing rocks show that sands, 
gravels, porous sandstones and limestones are the natural home 
of petroleum. 
The minerals and fossils of the oil-bearing strata of Penn- 
sylvania and Ohio are represented by a varied series of speci- 
mens. 
The distribution of the oil fields of the United States is 
illustrated on a small relief map, upon which the oil fields are 
outlined and to which tubes of characteristic oils from the vaii- 
ous regions are affixed. 
The products of one barrel of petroleum are arranged in a 
group according to the order in which they are obtained. These 
are (1) naphtha, (2) burning oils, and (3) residuum. The 
processes and products of further distillation of the latter will 
also be seen. The products include machine oils, vaselines, 
paraffin and coke. The products vary in character and amount 
according to the nature of the crude petroleum, hence the 
series shown illustrates onh^ a single petroleum. 
Much of the space in this hall is occupied by various finished 
products ready for sale, these being chiefly illuminating and 
lubricating 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. 
