FREE BOOKS

Author's List




PREV.   NEXT  
|<   15   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39  
40   41   42   43   44   45   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60   61   62   >>  
bullet, snugly imbedded where the force of the powder had driven it, and this was the only shot he had received while fighting for his country.--_Nashville Union_. * * * * * TEMPERANCE IN THE ARMY. We are gratified to learn that Gen. Taylor has totally prohibited the traffic in intoxicating liquors in the vicinity of the army. One fellow, persisting in the trade, was put in the guard house by Capt. Miles: and when liberated, on going to Gen. Taylor's tent with a complaint, was kicked out. He finally took marching orders _t'other way_. * * * * * MODES OF RAISING PONDEROUS ARTICLES. A wedge is considered to be the most simple of "mechanical powers," and is often used in cases where no other apparatus can be made to apply; as in splitting logs and other adhesive articles. If a massive rock is to be elevated from the ground, a wedge must first be driven between that and its foundation, preparatory to the application of levers. Yet the wedge is in most cases objectionable on account of the friction with which its use is attended. The next, and most common power applied for elevating buildings on large rocks, is the simple lever, commonly called a pry. This usually consists of a long straight beam or pole, one end of which is placed under the object to be raised, while a fulcrum consisting of a stone or block of wood, is placed under the lever, at a short distance from the object to be raised. The opposite extremity then being forced down by the weight of one or more of the workmen, a force is applied to the object to be raised, bearing the same proportion to that applied to the lever, that the distance between the fulcrum and the extreme end of the lever does to that between the fulcrum and the object. Levers made of iron, and simply denominated "iron bars," are commonly used in raising and removing rocks. A machine called a "bed-screw" is frequently used for elevating buildings. It originally consisted principally of a large vertical screw, which was placed on a foundation called the "bed," and was turned by levers; but many improvements and variations have been added, till, in some instances, the screw has been dispensed with, and a rack and pinion have been substituted. Some of the best in use consist of a vertical iron rack, which is occasionally forced upward by the teeth of a pinion: a geer wheel on the same axle with the pinion
PREV.   NEXT  
|<   15   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39  
40   41   42   43   44   45   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60   61   62   >>  



Top keywords:

object

 

raised

 

called

 

pinion

 

applied

 

fulcrum

 
distance
 

forced

 
simple
 
levers

foundation

 
buildings
 
elevating
 

driven

 
commonly
 

vertical

 
Taylor
 

straight

 
consists
 

consisting


proportion

 
variations
 

improvements

 

consisted

 

principally

 

turned

 

instances

 

dispensed

 

upward

 

occasionally


substituted

 

consist

 

originally

 
weight
 
workmen
 

bearing

 

opposite

 

extremity

 

common

 

extreme


raising

 

removing

 
machine
 

frequently

 
denominated
 
Levers
 

simply

 
vicinity
 
fellow
 

liquors