252 FIRESIDE SCIENCE. 



advantage to producers, its invention has not been 

 particularly advantageous to the consumers of 

 shoes. The interior " soles " of most cheap shoes 

 are now constructed of this material, and when 

 water penetrates into them, the result shows that it 

 is a poor substitute for good leather. We fear 

 that paterfamilias will never thank us for devising 

 " leather board." 



Twenty-three years ago, we engaged in a series 

 of extended experimental investigations upon the 

 hydrocarbon liquids, and one of the results of these 

 labors was the production of an apparatus fpr light- 

 ing buildings by employing air for the conveyance 

 of the light vapors to gas burners. From this in- 

 vention have come all the " portable gas machines," 

 " gasoline apparatuses," " air lights," " automatic 

 gas" devices, which are so numerous in our cities. 

 Every one of these is claimed as " very new," and 

 all are covered by " patents." The, perusal of an 

 article published in the " Traveller " newspaper of 

 Boston in 1849, describing the results of our labors, 

 will show that but few important improvements 

 have been made in our original devices, during 

 more than twenty years. Sixteen years ago we 

 constructed an apparatqs for extinguishing fires 

 by the employment of carbonic acid, or aerated wa- 

 ter under pressure. The instrument was almost 

 precisely similar to the one now claimed as new, and 



