The History: Today, Octave Chanute replied to Wilbur's letter of August 10th and sent him the name and address of a company in Chicago, Illinois which could supply Wilbur with spruce: Keith Lumber Company at the corner of 14th and Wood Streets. He comments to Wilbur that the it must be "sapwood, clear, straight-grained, and thoroughly seasoned". He tells Wilbur spruce is an eastern wood. Perhaps he might locate it in Cincinnati, Ohio.

He also sends Wilbur a "recipe" for varnish. He tells Wilbur that he has used "spar varnish" in the past, however, it did not shrink the cloth.

Varnish is a liquid substance. When spread on a surface it fills in tiny crevices and dries forming a hard (generally) clear coating. The varnish helps protect the surface. Wilbur is looking for a coating that can be used on the fabric surfaces. The preparation should shrink the cover and make it airtight.

Why does Chanute want Wilbur to use "sapwood, clear, straight-grained, and thoroughly seasoned"? What do these words mean?

Sapwood is the younger softer "living" outer portion of wood from a tree. It is more permeable and will be more flexible in shaping. Clear wood is not defected, blemished or has knots in it. Seasoned wood has been cut 6 or more months ago and dried. Cut wood has a high moisture content; seasoned wood, since it has been dried, has a low moisture content and weights less. Seasoning makes the wood hard and prevents it from warping (distorting). Straight-grained refers to the grain pattern on the wood. Wood cut on a straight grain is stronger than wood cut off-grain and can withstand breakage better than wood cut off-grain.

This combination of characteristics will help the Wrights bend and shape the wooden parts of their glider, yet be strong and minimize breakage.