The relevant terms of the tender which was accepted by the Executive Engineer were : "Item Rate tender for Works I/We hereby tender for the execution for the President of India of the work specified in the under written memorandum within the time specified in such memorandum at the rates specified therein, 'and in accordance in all respects with the specifications, designs, drawing, and instructions in writing referred to in Rule 1 hereof and in Class 11 of the conditions of contract and with such materials as are provided for by and in all other respects in accordance with such conditions so far as applicable." This recital was followed by a memorandum setting out the general description,, of the building in respect of whichthe window leaves, were to be supplied the estimated cost of thecontact and the description and the number of items of work offered to be done ' The items of work offered to be done were "providing and fixing" four different types of windows.