Then, if later any changes are called for by the client, they would be made at his expense, and he could raise no valid objection to standing the cost thereof.

In order to systematize the collection of data, each office should have a printed list of questions or memoranda to send to clients, agents, or field men; and these should be filled in as fully as practicable for each job. Such a list is given in Chapter XLVI of "Bridge Engineering," but lately the author, for the benefit of his future practice (especially in foreign countries) has materially elaborated this. He feels that it cannot well be made too full or complete, because the more one knows in advance about the governing conditions the better will he make his design.

Seventh. There should be established certain limits to the accuracy of all calculations, and these should be adhered to. The list of limits adopted in the author's practice is given on page 1377 of "Bridge Engineering."

Eighth. After each page of calculations is finished, it should be checked by the same computer so that, if he has made any error thereon, it may be corrected; and thus its effect will not be carried into any succeeding pages.

Ninth. All results should be roughly checked by the computer, using old records or diagrams, so as to ensure that no egregious blunder has been made.

Tenth. All calculations should be checked by an independent computer before being turned over to the drafting room.

Eleventh. Every record, book, pamphlet, and similar office possession should be filed and indexed so that it can be found at any time without delay.

Twelfth. Enough drawings should be made to enable the contractor to prepare properly and readily his shop drawings or other working drawings— but no more; and the preparation of shop drawings in the engineer's office should be strictly avoided. If they are made there so as to suit the style of one shop, they would probably not satisfy the idiosyncrasies of another— hence it is better to let each shop prepare its own shop drawings.

Thirteenth. It is truly economic to use standard parts whenever this is practicable. It saves time in the office and money in manufacture. Special sections of metal should be avoided, even if they apparently be economical; for generally time is far more valuable than a little extra metal. It is only in case of a large amount of duplication that special sections are legitimate.

Fourteenth. A simple style of lettering is both neat and economic, and the use of stencils and the printing press involves the saving of time and money.

Fifteenth. No unchecked drawing should ever be allowed to go out of the offices—no matter how pressing the call for it may be. The method of checking all drawings should be thorough and systematic, and it should invariably be followed.

Sixteenth. When changes on drawings become necessary, they should,