=115. Special Specifications.=—These have to do with problems, methods of construction, or materials peculiar to certain contracts or certain portions of the work. It frequently occurs that the construction of sewerage works will be let out under a number of contracts, or bids will be called for on different alternatives to which the entire Advertisement, Information and Instructions for Bidders, Proposal, and General Specifications are applicable. The special specifications will apply only to the contract in question, e.g., in some work done under the direction of the author, the sewer on one contract came within twelve inches of the surface of a highway. The special specification relating to this piece of construction, was: “Where crossing under the Chicago Road the pipe sewer shall be embedded in concrete as shown on the contract drawings. The concrete for this purpose shall be mixed in the proportions of one (1) part cement, three (3) parts fine aggregate, and six (6) parts coarse aggregate. Payment for the concrete so used will be made at the unit price stated in the accompanying Proposal.” In order to avoid confusion the special specifications are either incorporated directly in the Contract form, or follow the Technical Specifications and are grouped according to the contracts to which they apply. =116. The Contract.=—The contract is a brief instrument which includes a simple statement of the obligations of each party involved. The following is an example of a form in successful use: CONTRACT This agreement made and entered into this ____ day of ____ in the year one thousand nine hundred and ____ by and between the City of ____ by its duly constituted or elected authorities herein acting for the City of ____ without personal liability to themselves, party of the first part, hereinafter designated as the City, and ____ party of the second part hereinafter designated as the Contractor. WITNESSETH, that the parties to these presents each in consideration of the undertakings, promises and agreements on the part of the other herein contained, have undertaken, promised and agreed, and do hereby undertake, promise and agree, the party of the first part for itself, its successors and assigns, and the part ____ of the second part for ____ and ____ heirs, executors, administrators and assigns as follows, to-wit: Art. I. To be bounden by all the articles of the General, Technical, and Special Specifications applicable, and by the terms of the Advertisement, Information and Instructions for Bidders, Proposal and Contract Drawings hereto attached, and which are understood and acknowledged to be an integral part of this contract. Art. II. The work to be completed under this contract is ____