THE MODERN SKYSCRAPER 



NEW TOOLS AND NEW METHODS 



It is but a natural result of pressing demand that 

 in developing the construction of the new steel-frame 

 buildings new implements have been invented to fa- 

 cilitate the builder. To give a complete list of these 

 without discrimination as to their novelty and im- 

 portance is of course out of the question. On the other 

 hand no story of the progress of modern architectural 

 construction can approach completeness that fails 

 to give full credit to the various implements worked 

 by compressed air, and known as pneumatic tools. 

 In European countries, where the cost of manual labor 

 is relatively low, the time element does not enter 

 so greatly into the cost of construction. In America, 

 however, where wages are high, and in large cities where 

 the values of land make every day that a building site 

 remains idle a very material loss to the owner, rapid 

 construction is a necessity. 



It is to meet this demand that pneumatic tools with 

 various other time-saving devices have come into 

 prominence in recent years. 



In these pneumatic machines no new principle is 

 involved, as it is possible to obtain the rotary or re- 

 ciprocal motions with steam quite as well as with 

 compressed air. Indeed in factories where corre- 

 sponding stationary machines are used, such machines 

 are often driven by steam. But steam is too hot for 

 portable hand-mechanisms; and one of the great 

 advantages of pneumatic tools is that they can be made 



