730 Transactions op the American Institute. 



from one-quartei' to eight ounces, is pointed out by tlie indicator and 

 the revolving of the disc. ISTo calculation is required. 



It also informs you, in all instances, where prepayment of letters is 

 required, as well as all other important postal information. The 

 inaccuracies encountered hitherto in the spiral spring scales are 

 obviated in this invention by the adjustable indicator, which shows 

 absolutely and at all times the least derangement in the scale, which 

 can be easily remedied by reference to the directions upon the back 

 of each disc. 



As often as required to meet the chauges in the postal charges, a 

 new sheet will be printed and supplied to the purchaser at a moderate 

 charge. 



Carpet Cleaning Machine. 



Mr. John R. Ferguson then exhibited and explained his carpet 

 cleaning machine. It was so arranged that the carpet of any common 

 room, in moving over rollers, was beaten thoroughly b}'' two series of 

 wooden arms arranged opposite to each other. A long box was 

 placed underneath, in which a spray of water played, so as to arrest 

 and settle the falling dust. 



Woodbuky's Stkeet Locomotive Car. 

 Mr. Whiting, a prominent patent lawyer of Boston, Mass., exhi- 

 bited and explained for the inventor, Joseph P. "Woodbury's patent 

 street locomotive car, and gave reasons for the following points of 

 superiority claimed for this invention : 



1. The street steam car seldom gets out of order or needs repairs. 



2. It will seat forty passengers, and can carry over 100. 



3. It will run 100 miles per day, at a cost for fuel, oil, conductor 

 and engineer, not exceeding eiglit dollars, being less than one-half 

 the expense of doing the same work with horses. 



4. It will run easily around curves of thirty feet radius, and less, 

 if required ; without abrasion of the rail, such as is produced by all 

 other cars. 



5. It will not frighten horses, or make objectionable noise more 

 than horse cars; the machinery being out of view, and there being 

 no toothed gears, bell or whistle, and no puffing noise, or visible 

 escape from the exhaust steam. 



6. It is as safe, easy and comfortable as the long cars on steam rail- 

 ways; it is warmed by steam when needful; and it is free from jar, 



