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THE POPULAR SCIENCE MONTHLY 



Fig. 37. Fisher's Steam-Carriage, 1870. 



met with so many obstacles that even Hancock and Gurney, the most 

 ingenious, persistent, and successful constructors, gave up in despair. 

 Hostile legislation procured by opposing interests, and possibly also 

 the rapid progress of steam-locomotion on railroads, caused this result. 

 In consequence of this interruption of experiment, almost nothing 



was done during the suc- 

 ceeding quarter of a cen- 

 tury, and it is only within 

 a few years that anything 

 like a business success has 

 been founded upon the con- 

 struction of road-locomo- 

 tives, although the scheme 

 seems to have been at no 

 time entirely given up. 

 Messrs. Aveling & Por- 

 ter, J. Scott Russell, Boydell, and a few others in England, and Messrs. 

 Roper, Dudgeon, Fawkes, Latta, and J. K. Fisher, in the United 

 States, have all, at various times, labored in this direction. 



The last-named engineer designed his first steam-carriage in 1840, 

 and was still at work at the time of his death, in 1873. 



Abroad, a few firms have succeeded, within a few years past, in 

 making a business of considerable extent in constructing road-loco- 

 motives for hauling heavy loads, and in building steam road-rollers. 



While steam-carriages of high speed, and adapted to the trans- 

 portation of passengers, have not yet been successfully introduced, a 

 most promising start has been made in the application of steam to 

 the heavier kinds of work on the common road. 



The great impediments seem to be the roughness and bad construc- 

 tion of the ordinary highway, the damages arising from the taking 

 fright of horses, the engineering difficulties of construction, and the 

 limited power of the machine as it has usually been built. Hostile 

 legislation might perhaps be placed in the category, but we are prob- 

 ably sufficiently far advanced in civilization to-day to be able to secure 

 liberal legislation when the people shall be satisfied that the introduc- 

 tion of the road-locomotive will be of great public advantage. 



66. The capabilities of the road-locomotive are readily determined 

 by experiment, and the following is an abstract of the results of several 

 series of trials. 1 A trial of a road-engine was made by the well-known 

 French engineer, H. Tresca, in presence of Prof. Fleeming Jenkin, 

 and the report was submitted on January 15, 1868. The results were 

 as follows: 1. The coefficient of traction was about 0.25 on a good 

 road with easy grades. 2. The consumption of coal was 4.4 pounds 

 per horse-power per hour. 3. The consumption of water was 132.2 

 gallons an hour with the ten-horse engine. 4. The coefficient of ad- 

 1 Appletons' American Cyclopaedia, article "Steam-Carriage." 



