140 Miscellaneous Intelligence. 



half (or even a little less,) of the power the engines and battery are 

 capable of yielding. Each engine, calculated upon the basis of my 

 stationary engine, ought to give at the lowest estimate 12 horse power, 

 which would make the locomotive 24 horse power. The actual power 

 I have not been able to ascertain ; but the following data may serve to 

 give some idea of its power. The locomotive, with the battery fully 

 charged, weighs ten and a half tons. With the seven passengers taken 

 on the trip to and from Bladensburg the weight was eleven Ions, Under 

 the most favorable arrangements eight pounds are required to start a 

 ton on a perfectly level rail, and seven pounds will barely keep a ton 

 in motion. Ordinarily, upon railroads the allowance is ten pounds to 

 a ton, but this applies only to cars unincumbered by machinery. The 

 friction of locomotive machinery renders its draught far greater, and 

 can only be accurately ascertained by experinient in each case. The 

 magnetic locomotive, the first of its kind ever made, is imperfect, and, 

 from the newness and stiffness of all the work, it runs exceedingly 

 hard. We will take 200 pounds, which is below its actual power re- 

 quired to keep it in motion on a level portion of the road. A horse 

 power upon the usual estimate is 150 pounds 2J miles an hour, or 375 

 pounds 1 mile an hour. The speed of the magnetic locomotive is, we 

 will say, 15 miles an hour on a level road, (it has in fact made more,) 

 and its traction 200 pounds. We have then 375 pounds 1 mile an 

 hour for one horse, and 200 pounds 15 miles an hour for the locomo- 

 tive, which gives eight horse power. But the engine has more than 

 this. It has greater power at a slow speed, and must have, by all rea- 

 sonable estimates, twelve horse power; which, as I said before, is 

 about one-half its proper capacity. One of the most serious defects 

 arises from a want of insulation in the helices. After the engine was 

 placed on the road it was found neccessary to throw out of action five 

 of the helices, and these at the most important point in the stroke. 

 This difficulty could not be remedied without taking both engines en- 

 tirely out — an undertaking for which I had neither time nor means, as 

 the track with which we are now accommodated is soon to be filled up 

 for the purposes of the Eailroad company. Another serious difficulty 

 encountered was the breaking of the porous cells in the battery, caus- 

 ing a mixture of the two acids, and the it^terception of a large portion 

 of the power. I had great difficulty in procuring suitable porous cells, 

 and the manufacture of such as I needed was, after a great expense, 

 given up by two of the best pottery establishments in the country as a 

 thing impracticable. It was, however, accomplished through the inge- 

 nuity of Mr. Ari Davis, my engineer, but they were made of a weak 

 clay, and have now, from frequent use, become so much impaired as 

 to break from the slightest causes. Before we started two of them 

 broke, and the defect was only partially repaired. Not far from Bla- 

 densburg two more gave way, and detracted at once greatly from our 

 working power. On our return, about two miles from Bladensburg, 

 three more gave way, and we were reduced to at least one-half of our 

 power. The running time from Washington to Bladensburg was thirty- 

 nine minutes. We were stopped on the way five times, or we should 

 have probably made the run in less than thirty minutes. Going and 

 coming there were seven stops and three delays — that is, the engine 



