Hi David, from your description, I'd say that the Swiss method presented is not mill rule, the regulating scheme, to me, is mapping the joints or numerical scribe. To me, mill rule is another step towards industrial practice by the introduction of standardized material, accomplished through four sided planers. The carpentry practice is simplified even dumbed-down by reliance on regulated timber. The joinery is measured off the face you are working on not from reference sides or edges. It's necessary the the tolerance for milling must be tight, an order of magnitude closer than the cited Swiss example. The cutting relies on trusting the material and setting the depths on the tools, working from the surface. Joinery choice is up to the carpenter, free to use housings, tapers and embellishment.

The step beyond mill rule is CNC.

Roger,
I like your descriptions. Numerical scribe is a good way to put it, because it places it squarely in the traditions from which it has been derived. I could go into detail of the progression from full scribe to half scribe, into numerical scribe, but maybe you will just have to wait till august.

Thanks for the description of Mill Rule. I understand now what this is.

The practice of numerical or geometric mapping of the joints is very interesting to me and is something I have been looking into. It is a practice I think I would like to adopt.
Theoretically, numerical scribe and joint mapping could be executed with irregular timber as well, as long as a solid point of reference is established, like a datum line.

Sounds similar to mill rule, to me. Curious how or if "double cut" figures into the mess. In reverse, I have found myself thinking, while square ruling, these timber are so close I would't need to cut housing and reductions. Glad I found plumb line scribe.

Talking with my brother he gave me some good thoughts,

Square Rule carpentry is an idea that seems very typical of the Enlightenment era, which is precisely when it is supposed to have been invented. The idea governing this method is to seek the theoretical perfect timber that exists within each imperfect timber, an idea very much in the spirit of the times.

The numerical, mathematical, whatever you want to call it system on the other hand views each timber once it reaches the layout floor as a unique piece. It is what it is, and rather than forcing it to conform to our ideas of perfection we choose instead to work with it just as it is. Whereas the former could be viewed as an enlightenment idea, this could be seen as a Romantic approach to the same problem.

Both systems, I think, are examples of a building culture's response to the Industrial Revolution first and foremost. Both cultures started from pretty much the same point -skilled carpenters with scribe systems- and moved in the same direction, industrialized framing methods. Americans moved through scribe rule into balloon framing. The Swiss moved from scribed timber frames to a different type of timber frame scribed in a different way, then to a system of mapping and calculating the joints.

The American system is very democratic. Let's make carpentry accessible and easy to understand, something anyone can grasp. The Swiss system is very... Swiss...
Let's make our frames efficient, strong, but perfect. The Swiss carpenter I don't think would ever invent the square rule system, because a joint that has to be reduced to work would be considered poor and unsightly. A housed or reduced joint, you see, would be viewed as an unforgivable violation against the nature of the wood and the harmony of the frame (though they would never word it quite that way, just say, it doesn't look good)

Moving beyond this, My mind has been thinking in terms of mapped scribe systems all day and considering the possibilities. I want to do some experiments, I can see how you could accomplish the scribing of some pretty complex forms without the need of a scribe floor with this principle...

Tim,

I have often thought when working around the Square rule ideas,
Why not just eliminate the housings and reduction completely and make unique joints. Like some kind of illegitimate child of Square and Scribe rule carpentry. I was delighted to find out that someone was doing just this

On the other hand, while working with plumb line scribing I always think, why not simplify this whole process and just measure one point of the joint and map the whole thing out from there? That means, I scribe a joint, one point on each timber, and then geometrically or mathematically reduce things to regular angles (not regular dimensions)

What I end up with, I have always viewed as a sort of hybridized system.
I am happy to learn, this is an old idea. But it wasn't developed by combining the two ideas, it was developed in a different culture.

Hi David

As a framer, I am mostly self taught at yhe start. The first 15 frames or so were cut using a method of mapping and fitting. I had not heard of square rule at the beginning nor had I studied old square rule buildings. Mapping was, to me, endlessly an exercise of beating back uncertainty. I would draw up plans and know the frame cold but I could not say what the length of any piece was without surveying all the abutments. My hat is off to Mark Brandt, Mike Goldberg, Curtis Milton and Will Beemer for their presentations that opened up much needed insight into square rule and, for me, a far more clear layout of square rule.

In the early days of square rule, housings were not used, from my observation. Rather gains were cut in the non reference sides, without consideration for the joint, running past the joint horizontally and vertically. Joints most often beared on the tenon alone. The pieces all had an asymmetrical look, with an unworked ref side and gains in the non-ref side. My reasoning for housing is to provide support, restrain rotation and to hide shrinkage also to provide a more symmetrical look.

It has been a long evolving process for us all.

It is an evolving process, and that is what makes the craft, a craft...

There are different approaches to mapping, reference, etc. And people all approach it differently

The big driving difference I see between Swiss numerical scribe and American Square rule (really when I analyze the two, they are so strikingly similar in concept and practice, with just 1 or two slight, yet profound differences) is one that is centered on the way the two cultures look at a frame.

In America, a frame is a thing of pure utility. They made the frames to support the buildings, that was it. So you approach your joinery with a very practical viewpoint.
If it was a barn you built, it's ok if it is so rough and utilitarian. If it's a house, well you are going to wrap the whole thing and no one will see the frame (talking historically) so what does it matter how the frame looks.

Suddenly in modern times the frame has been thrust back into the spotlight, and these things matter again. But it seems to me, so much American mentality has been shaped by looking at the only frames you could actually see -barns.

But we have a very different situation in Switzerland. Here the frame is and always has been out in the open, visible, and a focal point of the architecture. It really really matters to a Swiss carpenter what the joints look like. The frame itself is very refined, neat, and well ordered. So of course so should the joints be.
Americans have developed this sort of romantic idea about a timber frame, having this rough frame of huge, hewn timbers, or otherwise some sort of rustic idealism. And that is fine, I am OK with that. It's just different. In Switzerland you would never do that, at least not within the context of traditional Swiss Holzbau. I totally understant the rugged idea. A lot of that comes from the American pioneering spirit.

So the idea of cutting reductions and housings makes perfect sense in American timber framing.

In Switzerland, its perfectly absurd.

Because the two cultures look at the frame with a totally different mindset.

And this is really important to this discussion. The Swiss are going to come up with an approach to layout that makes everything look ordered, regular, and well adjusted. They are not going to be satisfied with cutting a reduction at the joint to make it fit. Rather than do that, they would reduce the entire face of the timber. Now as to joints bearing on tenons, in Swiss carpentry they always do. BUT it's important to note that the design of the frame is such that timbers that need to transfer a lot of weight do not do so with a mortise and tenon joint, so the idea that this joint should be housed to support the weight more efficiently doesn't come into play at all. As we can see, there are a LOT of variables at play here, and it all comes down to the fact that here we have two totally different building cultures with extremely different ways of doing just about everything.
The old style of Swiss framing, Ständerbau, relies on heavy timber frames with a solid wood plank infill. The whole things is cut and fit together perfectly, the planks carefully fitted, and everything is neat and orderly. There is absolutely no room in this system for unorderly joints or irregular timbers. In the Canton of Bern, the planks were often pretty thick (like, say 4 or 5 inches) and fitted into the frame with tenons. You saved yourself a whole lot of work if you reduce the posts to very regualr dimensions, and can just cut the planks in a given cavity to a consistent size.
You have a parallel to this in log building just to the south, where the wall logs fit into heavy uprights framing the doors and windows. Again, with a tenon fitted into a groove in the upright. Here the process works in reverse, the wall is laid out on the ground, the location of the opening snapped, the openings measured for post height (calculated for settling) and then the posts are made to perfect dimensions, fitting into an opening that is cut perfectly.
So again to be clear, in the frames the posts were made perfect, then the planks measured to fit between them. In log buildings the logs were cut to perfect lengths, and the posts measured to fit to them. But all was greatly simplified by making sure the timber faces were as true as possible
I can attest this practice in log building as far back as the 11th century. In Ständerbau as far back as the 14th (probably much further, it's just that happens to be the oldest framed buildings still standing)

Going back to the frame as a thing of utility,
Americans have become used to that rough, rugged, utilitarian frame look. the American idea of timber frames is again shaped by looking at dusty old barns and thinking that's what it should look like. So it makes perfect sense that the idea of housed and reduced joints is acceptable. And that's not an insult at all, I am simply stressing the point that these two building cultures place the emphasis in entirely different places.

Again looking at the Swiss frame, we are a people that are mind-numbingly obsessed with detail. Little things matter a LOT, and everything has to be just right. Square rule carpentry just doesn't fit in that worldview. Again I don't say that as a criticism, but here to maybe explain when I say, why can't I just forget about the housing and map the joint, this is why. I'm working from a different mindset. I bi stolz e Schwyzer z sy

To me it just makes more sense to adjust the length of the adjoining timber. I know in my mind, if I make the joint face at the mortise regular and adjust the adjoining beam to match, it will work. But I am good at envisioning things, at taking complex things apart in my mind, disassembling them and seeing how they all fit together. It's easy for me, most of the time, to visualize how a change in one place affects the whole.


I would be interested in hearing more about the mapping technique you came up with. Even if it wasn't an ideal approach.

I'll just get the way back machine warmed up, Sherman get ready.

The first frames had material so poorly sawn, out of square edges, sawn thick to thin, sides plus or minus 5/8, there was no way to expect any consistantcy. So everything was first laid out to the exterior surface and then to interior center line. My partners and myself were all new to tf and so we had a number of control theories at the same time. But we were looking for steady clean joinery into faces that were not normal to bent or post line. So I tried to measure, record and compensate for variations. Pieces were cut long to allow for trim and scribe. At trial fit up, a lot of scribe and trim. Braces scribed and half lap half dovetail. Rafters were scribed off the deck. The aspect I did not like the most is the repetitive handling through bent line scribe, then post line scribe and then fitting in both directions. Anyhow our rookie making it up as we went was a model of confusion, but we got through it, three guys in the woods without a crane.

After two jobs, we fired the sawyer and lost one partner. Third house frame was a crane raising that went smoothly, we had better control and better material and more refined layout, still mapping and fitting, up to about 1995-96, when the cumulative effect of Guild workshops and class finally made inroads into my whole approach. So my critique of mapping has everything to do with me and my process and is not to be regarded as more general or specific comment on others work.

However, I find high bias and theorizing in your comments, David, that are just very far off the mark. Housings are not a definitive nor unique aspect of historical square rule. I have seen many historical square rule frames without any housings at all. I find gains that are well scaled to be graceful, flowing and even organic when performed with a shapely touch. Taking a housing out of the receiving member does not necessarily mean that the housed member is critically weakened. It is my view, that a housed beam is a much better supported beam with wide and even force distribution than a loaded tenon with a progressively distributed load.

So I ask you to try to think differently about gains. Considered the word ungainly meaning ugly, clumsy and unfit. Consider gainly meaning attractive, balanced and ready. If the carpenter is working with gainliness in mind then cutting gains becomes a matter of enhancement and preparation and not a matter of reduction and loss.

Hi DL, from my understanding the American framer performed a wonderful task. I would have to agree with Roger's last two paragraphs.

Roger I should clarify,

I am not trying to say I think of gains and housings as inferior,
I am trying to convey the totally different cultural approach between two lands that might explain the reasoning behind their choice of layout.

I personally Like the look of square rule joinery. It has a certain aesthetic that is pleasing.

However, in the context of a Swiss style frame it would strike me as out of place and not fitting with the architecture. Housed joints of any kind are exceedingly rare in Swiss frames.

Your experience certainly sounds interesting, and I completely understand your bias against mapping.
However, here we are comparing apples and oranges. The mapping in the numerical scribe approach is quite different, because you are not measuring and figuring out based off of inconsistent stock. You establish a super straight reference, often in Swiss archtiecture this is a matter of fact because of how the timber is treated. But if working outside this context or in roof joinery where irregular timbers may be more likely, you establish a reference with a chalk line. Having this reference, you can easily determine where things belong.

Now I should explain the nature of the timber here. Traditionally, Ständerbau is executed in hand hewn timber. It is hewn to very precise dimensions, and if it is for a roof or a barn somewhere, left at that (slight undulation, but generally very accurate timber) If it is for a house, very long (like 2 to 2 1/2 meters) planes are used to make the timber faces very very straight and smooth. So this is the place these carpenters are working from.

I don't mean to come off saying American carpentry is inferior, I was trying to express the totally different way these two cultures approach the idea of framing. Neither one is wrong, they are just different. And I am all for people loving what they are a part of, what they are connected to, attached to, etc.

And again to be clear, I am not saying square rule or the use of housings is inferior. It's just a different approach, one the other culture referenced would never have come to for the reasons cited. It's not an attempt to look down on American culture and framing, it's an attempt to explore the spirit behind two very different solutions to the same problem. Both of which are wonderful accomplishments, both of which have their place in the world. Both of which deserve our admiration and respect.

Just as there are a number of reasons I could not rectify the scribe rule system with Swiss style framing and architecture, neither would I attempt to impose the Swiss system on American architecture and framing. The way an American frame is designed, like Roger points out, a housing is a very very good idea. Not only that, the way these frames are organized the square rule system looks -right- and pleasing.

This isn't an attempt to look at the various methods mentioned -scribe rule, square rule, half scribe, numerical scribe- and decide which is better. It's an attempt to look deeply at what is going on behind the scenes, what the small factors are that affected their development, why it is done this way.