American School of Correspondence 
Textile Calculations 

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. The simplest method in use at present is the one used in the New England States, in which No. 1 woolen yarn represents 100 yards to the ounce, or yards to the pound, as a standard. The number of the yarn is the number of yards contained in one ounce, divided by 100. The yarn is spoken of as so many hundred yards to the ounce. Thus, no. 4 400 yards to 1 ounce. No. 4% z 450 yards to 1 ounce. No. 5 500 yards to 1 ounce.