Lady’s Travelling Box – Williamsburg Conference
At this week’s conference “Working Wood in the 18th Century” in Colonial Williamsburg, I was intrigued by Brian Weldy’s presentation on Thomas Sheraton’s drawing representations of the Lady’s Travelling Box. It was necessary for Brian, and Mack Headley (master cabinetmaker), to dissect Sheraton’s drawing to create their own version of this box.
Brian showed Sheraton’s drawing as depicted in his book “The Cabinetmaker and Upholsterers Drawing Book”. He also illustrated , with pencil, drawing board, T-square, and compass, how to decompose the strange drawing format, into critical dimensions necessary for the construction.
I suppose the engineering background drives my interest in this strange perspective drawing representation, and how one could discover dimensional information necessary for building the box.
I fired up SketchUp on my first day back home and imported the Sheraton drawing shown above.
Since this is not a photo rather a corruption of a perspective sketch, I suspected that SketchUp’s Photo Match capability would not be much help. I tried anyway, and indeed found out quickly that it wouldn’t produce acceptable results. It’s as if Sheraton decided to make the front face of the box in Orthographic View, and then draw out the rest of the box in single point perspective. That’s quite a combination within one sketch.
Sheraton provides a scale on his sketch, so this is very helpful in determining component dimensions. Since the front face of the box is straight-on in view, it’s easy to discover the width and height of the box. The trick is determining the depth of the box.
The key to this unknown is the fact that the top of the box is perpendicular and also facing the front. Its dimensions are reduced due to the top being located at the back edge of the box. The open top’s height is proportional to the actual real depth of the box. To find it’s real height I used the vanishing point and guidelines to project the height at the front location as it intersects the picture frame.
See the following video of this process of determining key overall box dimensions.
Note that I did not use 3D at all in this exercise – only 2D – that’s extremely rare for me.