76 LABOR AND CONTRACTS 



price per square yard of macadam pavement laid complete, 

 etc., basing his total estimate on the above approximate 

 estimate as given by the engineer. This system is elastic. 

 The amounts of work under each heading can be increased 

 or decreased, although not indefinitely. The increase or 

 decrease permitted is usually not more than 20 per cent. 

 If a contractor has bid low on earth excavation and high 

 on sewers, he naturally would object to the amount of 

 earth excavation being greatly increased or the lineal feet 

 of sewers greatly reduced. Under the unit system it is not 

 necessary to prepare complete plans of the work before it 

 is begun. 



METHOD OF PROCEDURE 



In contemplating the execution of a piece of engineer- 

 ing work, three questions must be decided by the board 

 or commission having power. These are, first, What will 

 be the cost? second, Is it advisable to do it? and third, 

 Shall it be done by day labor or by contract? 



In determining the first question the engineer is con- 

 sulted and asked for a report on the cost. This report 

 may be made immediately in some cases, but in others 

 considerable time may be required for its preparation. 



After knowing the cost, the advisability of doing the 

 work is discussed and a decision arrived at. 



The question as to whether the work shall be done by 

 day labor or by contract is usually referred to the engineer. 



THE ADVERTISEMENT 



An advertisement of the work is inserted in the local 

 papers and sometimes in one or two of the leading technical 

 journals. Unless the contract is to be let by the lump sum, 

 the amounts of all the items are stated. The advertisement 



