Lost Art Press

Category: From Truths to Tools

Spiling Batten

Posted on by meghanlostartpress

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This is an excerpt from “From Truths to Tools” by George Walker and Jim Tolpin; Illustrated by Andrea Love. 

Just out of curiosity, let’s see what happens when we draw a circle, then switch the dividers’ legs around. Being sure to keep the same setting (i.e. the radius of the first circle), we set the point anywhere on the rim and swing the other leg around to construct a second circle.

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We now have before us two circles of the same size, which yields the birth of “symmetria” (symmetry) – one of the most useful and foundational principles in geometry (not to mention keeping the universe itself intact).

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The intersection of the symmetrical circles at each other’s focal points is the geometric truth underlying a powerful layout tool called a spiling batten. To see how this wool works, follow the steps in the drawing.

1.) Swing an arc (about one-third of a circle) from a focal point.

2.) Keeping the same radius. swing back a little arc from any place on the first arc.

3.) Swing back another arc from a second point on the first arc. The intersection of these two small arcs is the location of the original focal point.

Be aware that you need to be careful to maintain the same setting for all these arcs.

A common application of spiling in boatbuilding is in the fitting of a boat plank perfectly between two other previously installed planks. We begin by tacking in place a thin piece of wood (the spiling batten) in the opening between the planks. Next, from station points we’ve made on the upper and lower planks (usually at the centerline of frame locations) we swing an arc onto the batten.

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To avoid errors due to a change in the divider setting, we will record the divider span somewhere on the the batten to provide a double-check.

When we are done making arcs from all the station points, we remove the batten and lay it on the stock to be cut to shape. Then we swing two arcs from each arc drawn on the batten.

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The intersection of these arcs will be the location of the original station point. Finally, we’ll use a bendable length of wood to connect the transferred station points onto the stock. Cut to the line and we are rewarded with a ready-to-plane-to-perfect fit.

— Meghan B.

Geometry in Time for the Holidays

Posted on by fitz

Christ the Geometer

In the spirit of the holidays, let’s perform some simple, ancient geometry to create the iconic symbols of the two religions celebrating major holidays this month. You’ll need only a compass, a straightedge, a piece of paper and a couple of candles to illuminate your work. In chronological order (in more ways than one) let’s start with Judaism’s Star of David:

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Begin with a circle and mark the focal point. We have actually started with the symbol for Ra, the ancient Egyptian sun god for whom winter solstice was celebrated for thousands of years prior to Judaism – but that may or may not be another story.

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Now draw a line vertically through the focal point (i.e. a diameter) and mark its intersection points at the rim.

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Next set the compass to span from one of the rim intersection points to the focal point and swing an arc through the rim as shown. Mark the arc’s intersection points.

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Repeat from the other rim intersection and mark two more rim points.

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Connect all the rim points across the circle.

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Erase the circle rim, diameter line and interior arcs and you are left with the Star of David. 

Now let’s create the Christian cross – also from the intersection of line and circle:

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Again we’ll start with a circle (which came to represent the heavens), but this time we’ll draw the diameter line at about a 45° angle.

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Construct another diameter line at a right angle to the first. Use the intersecting arcs method (or just fudge it, I won’t tell).

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Connect the rim intersection points to create a square (which traditionally represents the four directions, the four seasons and the earth itself).

 

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Now bisect the lower horizontal line and extend the bisection line from the focal point down past the lower rim of the circle.

 

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We’ll set our compass to the span between the rim intersection point and focal point, and swing a second circle. (A second of a pair of circles traditionally represented the Dyad … the reflection, the knowing of the first circle called the Monad (all one/alone).)

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When we erase most of the lines we are left with a cross … a symbol of the melding of heaven with earth. Or for the math geeks: a pairing of a diameter line (2) with the non-terminating (i.e. irrational) square root of two.

Note: This geometric construction of the cross is not historical but rather the product of my imagination.

— Jim Tolpin, one of the authors of “From Truths to Tools“

Carvers & Compassers: Save This Date

Posted on by Lost Art Press

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I am pleased to announce that Mary May and George Walker will be at the Lost Art Press storefront on Dec. 9 to celebrate the release of their new books.

Mary, the author of “Carving the Acanthus Leaf,” and George, one of the authors of “From Truths to Tools,” will each give a short presentation on their work that evening, answer your questions and sign books. Lost Art Press will provide drinks and snacks for this free event.

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Only a limited number of people can attend (fire marshal’s orders), so we will offer free tickets to this event starting at Friday at noon Eastern time.

Note that Saturday, Dec. 9, is also the last open day for 2017. So if you need books signed by me (note: I am happy to fake any signature, including: Tommy Mac, Roy Underhill and André Roubo) that’s the day to do it.

We hope you can come!

— Christopher Schwarz

‘Carving the Acanthus’ Will Ship Early

Posted on by Lost Art Press

CTA_mockup_1000We just received word from our printer that “Carving the Acanthus Leaf” by Mary May shipped to our warehouse yesterday, two weeks ahead of schedule.

That means our warehouse will receive the books next week and we should be able to start shipping out pre-publication orders at the end of next week or so. As a result, the special pre-publication offer will end on Nov. 13. So if you want a free pdf of the book in addition to the hardcover copy, order before then. After Nov. 13, the pdf will cost extra.

Double Book-release Party
We are holding a special book-release party for “Carving the Acanthus” and “From Truths to Tools” on Dec. 9 at the Lost Art Press storefront in Covington, Ky. Mary May and George Walker will be there to sign books, give presentations on their work and answer your questions. We’ll post details on this free and fun event in the next couple weeks. So save the date.

Next up for Lost Art Press
We have two books that are now being designed: Richard Jones’s opus on wood technology (still wrestling with the title on that one) and Joshua Klein’s book on Jonathan Fisher, “With Hands Employed Aright.” We hope to have both of these books sent to the printer by the end of the year.

A little farther down the pipeline: Jögge Sundqvist’s “Sloyd in Wood” and my greatly expanded edition of “Roman Workbenches.” Both are almost ready for the designer. It looks like 2018 is going to be busy.

— Christopher Schwarz

Solving Spans with Sticks, Strings, Sightlines & Stones

Posted on by fitz

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In this excerpt from our book, “From Truths to Tools,” we show how the carpenter/geometers of antiquity used the simplest of tools – those mentioned with almost annoying alliteration in the title – to solve for an unknown distance.   

Note that the solution does not necessarily require a number as it physically reveals the length of rope or timber needed to reach the span point. Here’s the excerpt:

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