The privilege is commonly reserved in all public work of rejecting any or all bids, and this has led to the common belief that in all work the contract must be awarded to the lowest bidder. Except in a few cities or states where it is made compulsory to award all public work to the lowest responsible bidder, the mere estimating on work and tendering a bid imposes no obligation whatever on the owner, who can reject any or all bids, or accept the lowest, highest or any other tender, without in any way being liable. The bid tendered by a plumber in competition with others, is simply a specific offer and unless there is an unconditional acceptance, there is no contract and no cause of action. Further, the owner is under no obligation to specifically reject the offers he does not accept. His neglect to accept them operates as a rejection.