Really Big Dovetails…but Why?

When the question is “why,” “because” is seldom the answer sought.  Of course, it was “because” that came to my ears with a frustrating frequency in response to so many questions asked in childhood and, as it was then, it seems to be again as a historically informed cabinetmaker.  We can often learn a lot about how a piece of furniture was designed and built through careful study of measurements, tool marks, and so on.  Every so often these “hows” point to why a particular shop made a particular piece this way or that way at some particular moment in time.  Far more often however, our sense of how something was executed leads – at best – to only a vague understanding of why.

The question that has been weighing on my mind of late is this:  Why did Peter Scott build the bookcase for this late 1720s desk the way that he did?  More specifically, why did he join the bottom to the sides with elephantine dovetails?

Here’s my version of the walnut desk and bookcase in its current state of incompletion.

The desk and bookcase thus far

Here are a couple of views of the meaty dovetails on the bottom of the bookcase, which needs to be raised up from the bottom of the sides to make room for candle slides.

Large dovetails on Bookcase bottom

Large dovetails up close

I was hopeful that cutting the joinery would yield some sort of cabinetmaking epiphany…Nope! Just a few more reasons why not to make a bookcase this way.

Before pressing on with how I cut these dovetails, a few words about Scott and the original desk are in order.  Peter Scott is the earliest documented Williamsburg cabinetmaker: he was here working by 1722 after receiving his training in Britain.  This desk, made for the Baytop family of Gloucester, VA (across the York River from Williamsburg) is the earliest such piece attributed to any Williamsburg maker and is currently owned by the College of William and Mary.  Stylistically and structurally, it is the forbearer of the kinds of case pieces we typically built in the third quarter of the 18^th century.  While Scott’s appearance in Williamsburg predates the Hay shop by nearly three decades, he was also our contemporary – and presumably competitor – working up until his death at 81 years of age in 1775 (the Hay shop closed in ’76).  I’ll have a lot more to say about the desk in the coming weeks, but what about those dovetails?

In essence this joint is a pair of sliding dovetails and that’s how I approached the process of making it with one exception.  Typically I like to cut dovetails pins first and sliding dovetails tails first.  Here, I opted for pins first with good reason, but more on that later.  After laying out the socket (I’m demonstrating here on some scrap) I made a relief cut at the two corners along the base line.  As the out of focus shot below tries to illustrate this can be done with a center bit in a brace or a mortise chisel.  We’ve seen marks from center bits in sliding dovetails on 18th century table pedestals.

Getting started with a mortise chisel or center bit

Next, I carefully sawed out the slope of the joint beginning with the front corner and working back. The first step provides space to work the saw.

Sawing the joint

After making some quick relief cuts, I chiseled along the base line to cleanly define that boundary.

Chisel the baseline

The rest of the material was rapidly chiseled out and the recess was cleaned up with a router plane (I’m only showing half the joint here).

Excavate

Clean up bottom with router plane

Finally I used a broad, sharp paring chisel to clean up the sloped edge of the socket.  By starting at the front corner and working back towards the baseline, I could really control the cut by using the chisel’s flat back as a reference surface.  Of course this is initially referenced off the front corner of the socket, which was the only part of the joint that I could see during sawing.

If this were a true sliding dovetail, I’d want the joint to be perfectly tight up front and a little looser back toward the baseline.  Here, because the bottom board is far thinner than the socket is long I need the joint to be tightest back at the baseline and because the front edge of the socket is used to mark the tails it needs to line up perfectly with the back.  In other words there can be no taper to this joint as is often the case with a sliding dovetail!  If I cut the tails first my saw work for the socket would have had to have been nearly perfect.  By cutting the socket first I can fuss with it until everything is straight and square without worrying about the exact size of the tails.

Pare slope

Half of a finished socket

Why do any of this?

Well, as stated above, the bottom needs to be raised up to accommodate the candle slides that mount below the bookcase (see the first picture).  But why not install the bottom with a sliding dovetail that runs across the sides of the case from front to back?  Oh and by the way, a traditional sliding dovetail would not be prone to shifting down over time with gravity and the weight of all those books on the shelf.  Of course, these dovetails do help keep the bookcase locked together and with some added glue blocks the demands of gravity can be met.    Perhaps cutting two big tails seemed like a more expedient approach than making sliding dovetails, but judging from the construction of the desk itself Scott knew how to cut long sliding dovetails with ease.  One final and strong possibility is that this is how Peter Scott learned how to construct a piece like this, but that’s basically just a dressed up way of saying “because!”

Why am I constructing the desk this way?  Because that’s how Peter Scott did it, but the whole point of historically informed cabinetmaking is not to rest on unthinking answers like this.  Maybe after going through the whole process I can’t answer my initial question, but I’ve answered and asked a slew of new questions I did not think of in the first place.  At the end of the day I’ve got some really big dovetails, some new techniques in my bag, and an increased awareness of 18^th century techniques.

Curiosity, according to the old saying, is deadly for cats, but it’s the lifeblood of period furniture making.

BP.