328 SHOP DRAWINGS AND RULES 



The above scheme will necessarily have to be modified more or 

 less according to circumstances ; for example, where a building has dif- 

 ferent sections or divisions applying on the same order number, in 

 which case each section or division should have a distinguishing letter 

 which should prefix the mark of every piece. In such cases it will per- 

 haps be well to omit other letters, such as N., $., etc., so that the mark 

 will not be too long for easy marking on the piece. In general, how- 

 ever, the scheme should be followed of marking all the large pieces, 

 whether alike or not, with a different mark. This would refer to pieces 

 which are liable to be hauled immediately to their places from the 

 cars. But for all smaller pieces which are alike, give the same mark. 



For architectural buildings adopt the following general scheme of 

 marking: The basement "A"; first floor "B" ; second floor "C" ; then 

 mark all the pieces on the first floor B. I ; B. 2 ; etc. ; columns between 

 first and second floors B. C. i ; B. C. 2 ; etc. 



It will greatly aid the detailing, checking and erection if small sec- 

 tions are made showing the principal connections, such as girt connec- 

 tions, purlin connections, etc. 



The erection plans of a mill building drawn in accordance with 

 these rules are shown in Fig. 167 and Fig. 168. 



CHOICE OF SECTIONS. In designing, it will be found eco- 

 nomical to use minimum weights of sections, and to use sections that 

 can be most easily obtained. As small a number of sizes should be 

 used as is practicable where material is to be ordered from the mill, 

 if good delivery is to be expected. The ease with which any section can 

 be obtained in a mill order, depends upon the call that that particular 

 mill is having for the given section. If there is a large demand for 

 the section, it will be rolled at frequent intervals, while if there is 

 little or no demand for the section, the rollings are very infrequent and 

 a small order may have to wait for a long time before enough orders 

 for the section will accumulate that will warrant a special rolling. The 

 ease with which sections can be obtained will, therefore, depend upon 

 the mill and the conditions of the market. The standard and permissible 



