88 ANNUAL OF SCIENTIFIC DISCOVERY. 



Extensive manufactories of coal-oil are now in operation at New York, 

 Boston, Baltimore, Cincinnati, Philadelphia, Pittsburgh, Brooklyn, and many 

 other places. The production will doubtless continue to augment, as the 

 demand for prime qualities now exceeds the supply. It is to be regretted 

 that much of the oil produced in this country is impure, containing a super- 

 abundance of the heavier hydro-carbons, which, except they are removed, 

 produce smoke and fill the apartment with unpleasant odors. The remedy 

 for these evils will be applied, and re-distillation, or some less wasteful and 

 more efficient process of purification, will be adopted, as competition is 

 excited and the manufacture progresses. 



Of coal-oil lamps and burners, about 150,000 dozen are estimated to be in 

 use, each lamp consuming about four gallons of oil during the year. The 

 amount of oil burnt averages consequently 7,200,000 gallons a year, or about 

 20,000 gallons every day. To make 22,750 gallons of burning oil requires 

 75,000 gallons of crude coal-oil, or a consumption of 00,000 bushels of cannel 

 coal. The erection of crude oil and refining works to make this quantity of 

 oil each day will cost $3,000,000; but the actual outlay for the oil-works at 

 present in operation does not fall short of $8,000,000. The value of chemi- 

 cals used in the purification of coal-oil will amount to over $2,000 per day. 

 The number of barrels used to hold coal-oil will be between 500 and COO, 

 representing the value of $1,000 and the labor of 400 men. The aggregate 

 value of the coal-oil itself will amount to $16,000 per day, or more than 

 $5,000,000 a year. This, too, does not include heavy oil and paratfine, the 

 sale of which is limited and uncertain. The number of workmen employed 

 in the several coal-oil works in this country will reach 2,000; that of the 

 miners engaged in mining cannel, 700 more. Besides these, a large force of 

 men is employed in making lamps, burners, wicks, chemicals, etc. Gas 

 Liyht Journal. 







THE AMERICAN SCREW CLOCK. 



Large sums are annually paid in this country for fancy clocks imported 

 from France and Germany, the value of which commonly consists more in 

 their cases and tinsel work than in the excellence of their machineiy and the 

 accuracy of their movements. The cheap clocks of Connecticut manufac- 

 ture, the wheels of which are cut out by dies, are quite as good time-keepers 

 as most of the foreign clocks, and take their place in this country, and to 

 some extent in Europe also, where correct time-keeping at least possible cost 

 is alone desired. In these, and in watches made also on the same principle 

 of multiplying the parts by machinery, so that the pieces may be put toge- 

 ther indiscriminately, the American manufacture has of late years made 

 great progress, lessening the foreign importations, and greatly increasing 

 the use of these valuable instruments. But in ornamental clocks we are still 

 dependent upon European manufacturers. 



We therefore welcome the introduction of a beautiful ornamental clock, 

 upon an entirely new principle, of great simplicity of design, and so con- 

 structed as to possess the accuracy of movement of a chronometer watch. 

 Its works, however, are fully exposed to view under the glass that incloses 

 them, and a better opportunity is thus afforded of learning the principles 

 upon which this useful machine is constructed than from any other clock 

 in use. 



The clock to which we refer is a recent invention of Mr. James Tuerlynx, 



