ISTRODUCTION 3 



Perhaps the most common mistake made by beginners is a 

 faihiro to give sufficient time to the study of proportions. No 

 amount of care in representing details will compensate a poorly 

 proportioned outline. The first outline sketch should there- 

 fore be made lightly to admit of erasures and additions as the 

 study progresses. The appearance of drawings improves rapidly 

 as one's sense of proportions becomes more dependable. The 

 instructor may be asked to pass upon general proportions before 

 details are represented. When the proportions of the outline 

 seem satisfactory retrace the corrected outline with an unbroken 

 clear line. Details of structure may now be located with constant 

 comparisons of the drawing and the object. Use light lines at 

 first, following with heavier ones later. 



Keep in mind the fact that drawing is only a means to an end, 

 not the object of laboratory work. Drawings better than words 

 reveal to the instructor the student's progress and the difficulties 

 he encounters. 



The appearance of a good drawing may be spoiled by labeling 

 in a careless manner. Good results may be obtained by con- 

 sidering the following suggestions: 



1. Printed or written names of parts should be connected by 

 guide lines with the parts they represent. 



2. A broken line is preferable as a guide line. 



3. Never allow guide lines to cross. As far as possible guide 

 lines should be parallel. There is no substitute for a ruler in 

 drawing these. 



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