OHIO OIL GAS. 



tember, 1799, the first territorial legislature assem- 

 bled at Cincinnati, under the ordinance of congress 

 of July IS, 1786, for the government of the territory 

 of the United States north-west of the river Ohio. 

 April 30, 1802, congress passed an act authorizing 

 the calling of a convention to form a state constitu- 

 tion for that part of the North-West Territory which 

 now constitutes the state of Ohio. On the first of 

 November following, the convention met at Chili- 

 cotlie, and formed the present constitution (for which 

 see Constitutions of the United States). In several 

 parts of Ohio are futind remarkable antiquities in the 

 shape of mounds, or tumuli; and also remains of 

 ancient forts. For a description of these, see the 

 article Tumuli. 



OHIO, a river of the Mississippi Valley, is formed 

 by the confluence of the Alleghany and the Monon- 

 gahela at Pittsburg, in the western part of Pennsyl- 

 vania. It flows with a gentle current, generally in a 

 south-western direction, but with a very serpentine 

 course, and unites with the Mississippi in latitude 

 37 N., and longitude 88 52' W. Its length from 

 Pittsburg to its mouth, is about 900 miles, including 

 its windings ; but the direct distance is only 614 

 miles. Its breadth varies from 400 to 1400 yards. 

 At Cincinnati, it is about 800 yards, which is nearly 

 its average breadth. It is very well suited to boat 

 navigation, although its numerous windings render a 

 passage upon it rather tedious. The current of the 

 Ohio is remarkably gentle, and is broken by falls or 

 rapids only at Louisville, in Kentucky. At this 

 place, the water runs with great rapidity for several 

 miles ; yet the current is not so broken as entirely to 

 prevent the ascent of boats. The whole perpendicu- 

 lar descent in two miles is twenty-two and a half 

 feet. The canal around these rapids (for an account 

 of which see Louisville) greatly facilitates the navi- 

 gation of this river. Letart's rapids, twenty-five 

 miles below Shade river, form a slight obstruction in 

 some stages of the water. Numerous islands, large 

 and fertile, are embosomed in the Ohio. Its annual 

 range, from low to high water, is about fifty feet : the 

 extreme range is about sixty feet. When lowest, it 

 may be forded at several places above Louisville. 

 It is generally lowest in August, September, and 

 Ociober, and highest in December, March, May, 

 and June. Near Pittsburg, it is frequently frozen 

 over for several weeks during winter ; and this has 

 been the case more than 400 miles lower. Generally, 

 the navigation upward is suspended by floating ice 

 during eight or ten weeks of each winter. Its cur- 

 rent, when the river is at its mean height, is about 

 three miles an hour ; when higher and rising, it is 

 more ; when very low, it does not exceed two miles 

 an hour. The numerous islands form no serious 

 obstruction to its navigation, except at low water, 

 when the bars and ripples connected with them are 

 somewhat dangerous. Steam-boats have been found 

 to be peculiarly well adapted for its navigation. The 

 whole number of steam-boats built on the western 

 waters is 348 : the number running in 1831 is 198. 

 Of these, sixty-eight were built at Cincinnati, sixty- 

 eight at Pittsburg, twelve at New Albany, and nearly 

 all the others in Ohio and Kentucky. A great part 

 of these boats are employed in the commerce of the 

 states bordering on the Ohio ; but they also connect 

 with it the commerce of the states on the Mississippi. 

 The tract of country through which the Ohio flows is 

 one of the richest and most delightful on the globe. 

 The wealth of the neighbouring states is easily trans- 

 ported to this channel by the numerous navigable 

 rivers which it receives, and is thence conveyed to 

 New Orleans the grand commercial emporium of 

 the Mississippi Valley. 



OIL. The general characters of this substance 



are inflammability and insolubility in water. Oils 

 are distinguished into two classes, fixed or fat oils 

 (see l'"at), and volatile or essential oils. (See Essen- 

 tial Oils.) The former class do not rise in distilla- 

 tion at the heat of boiling water, while the latter rise 

 into vapour at all degrees of temperature. When 

 exposed to the action of the air, the oils by degrees 

 lose their liquidity, thicken, and occasionally become 

 hard. Such as become indurated so as not to stain 

 paper when applied to it, take the name of drying 

 oils ; such as linseed oil, poppy-seed oil, nut oil, &c. 

 Such as do not harden in this way are called unctwui 

 oils ; as olive oil, almond oil, rape-seed oil, &c. In 

 this change no water is formed ; some carbonic acid 

 is evolved, but not nearly equivalent to the oxygen 

 absorbed. The recent fixed oils exercise on oxy- 

 gen hardly any action for a long time ; but they sud- 

 denly suffer a change of state, which enables them to 

 absorb at least 100 times more of it than volatile 

 oils would do in the same time. A layer of nut oil, 

 three lines thick and two inches in diameter, laid on 

 mercury in the shade, in pure oxygen gas, absorbed 

 only a volume equal to thrice its own, during eight 

 months, namely, between December and August ; 

 but, during the ten following days, it absorbed sixty 

 times its volume. This absorption continued to pro- 

 ceed with more slowness till the end of October, 

 when the further diminution of the gas became insen- 

 sible. By this time the oil had absorbed 145 times 

 its bulk of oxygen, and had formed twenty one 

 volumes of carbonic acid gas. No water was pro- 

 duced, but the oil had become a mass of transparent 

 jelly, which did not stain paper. This sudden change, 

 at a certain crisis, in the state of the drying oils, ex- 

 plains the spontaneous inflammations which they are 

 known to produce, and of which the volatile oils 

 afford no examples. 



OILEUS; one of the Argonauts. See Ajax. 



OIL GAS. It had long been known that wax, 

 oil, tallow, &c., when passed through ignited tubes, 

 are resolved into combustible gases, which burn with 

 a rich light. Messrs Taylor and Martineau were 

 the first to avail themselves of this fact, in the con- 

 struction of apparatus for generating oil gas on a 

 large scale, as a substitute for candles, lamps, and 

 coal gas. The advantages of oil gas, when compared 

 with coal gas, are claimed by these gentlemen to be 

 the following : The material from which it is pro- 

 duced containing no sulphur or other matter by which 

 the gas is contaminated, there are no objections to its 

 use on account of the suffocating smell in close rooms. 

 It does no injury to furniture, books, plate, pictures, 

 paint, &c. All the costly and offensive operation of 

 purifying the gas by lime, &c., are avoided ; nor does 

 the metal of which the conveyance pipes are made 

 receive the slightest injury from oil gas. The econ- 

 omy of light from oil gas is thus stated : 



Argand burner, oil jfas, . . id. per hour. 

 Argaiid lamps, spermaceti oil, 3d. 



Mould candles, 3jd. 



Wax candles. l4d. 



The oil gas has a material advantage over coal gas 

 from Us peculiar richness in olefiant gas, which ren- 

 ders so small a volume necessary, that one cubic foot 

 of oil gas will be found to go as far as four of coal 

 gas. This circumstance is of great importance, as it 

 reduces in the same proportion the size of the gas- 

 ometers which are necessary to contain it. This is 

 not only a great saving of expense, but is a material 

 convenience where room is limited. The iron retorts 

 employed, after a slight using, cease to afford the 

 gas, from an alteration produced on the iron by the 

 action of oil at a high temperature, and require the 

 introduction of fragments of brick, mingled with the 

 ! oil, which produce a great increase of the decom- 



