I was reading through the report on the 2003 guild tour of France,
In it, there is some mention of the layout methods and something caught my attention,
At one point, one of the carpenters speaks of a half-scribe system where the joints are laid out in standardized spacing,like square rule, while only the lengths of the timbers are scribed thus eliminating the need for housings.
Then mention was made of the 'german system' used in the alsace region. It wasn't detailed exactly what was meant by this,

I am familiar with a half scribe method, and am somewhat confused by the french scribe system. I am accustomed to a system where the timbers are carefully cut and planed to exacting dimensions and the joints laid out according to reference lines. -The mortises can all be cut off of these reference lines, without any need for scribing timber irregularities. So cutting mortises works just like cutting them in square rule.
Only the timber lengths are laid out with a scribe system -after mortises are cut into the timbers, they are laid out in an assembly and their lengths marked according to any slight bow that may exist in the adjoining timber. This requires only a single reference mark on the tenon end of the timber, very fast and easy.
The result of this is very perfect joints with no housings. This requires you to start out with very near perfect timbers, though. But in German, Swiss, and Austrian carpentry that is normal. Today with precision milling and planing, that's no trouble at all. The goosewing axe was developed for the purpose of creating such exacting timbers. German and Central European hewing techniques are focused on precision.

I have often wondered when looking at these, could this German style of frame layout be the REAL origin of square rule in the United States? Could US square rule be simply a logical advancement of the German method, or an means of applying the German technique to English framing systems? Is it a coincidence that square rule appears in English-style American framing a short time after the mass immigration of German-speaking people to the colonies? The German system has been around so long in some regions, we really have no knowledge of any other method they might have used beforehand.

I like this method, it's simple and I understand it. full scribe to me is burdensome and tedious. This is quick and easy, and effectively eliminates the most troublesome and time consuming aspects of both methods.

That said, square and scribe rule as Americans know them are excellent when faced with very irregular timbers. The German system can't deal with that without the addition of extra steps. The first step of the German system is to make the timber very regular.

DL,
This would be good topic to discuss at the Conference in August.
Since I wrote the article I feel I should reply.
Square Rule was developed, as I understand it, to use with roughly (not precision) square hewn timber. The French (and English) scribe system is still being used for restoration work (and much new) that is still done with very irregular timber, for the "look" as well as the historical accuracy. I would think the Germans and others must still run into this and would default to scribing after the timber gets so irregular.

Will,
I know in Switzerland at least, irregular timber is rejected or cut up into smaller pieces where its irregularities do not matter.

The walls were generally framed with wood plank infills, and highly refined. Precision was absolutely necessary.

Half-timbered, like Fachwerk (Switz. Riegelbau) structures use very short timbers.

I can'r say as much as to how it's done north into central Germany

But if they're doing a historically accurate repair or replacing timbers, or a reconstruction, wouldn't they use timber that was irregular if that's what the previous was?

Jörn Wingender's article on German Timber framing in Timber Framing #48, page 6 shows "Wild man" curved timbers and states: "Straight,fast-growing spruce began to replace the dominant
'old-growth' oak and beech forests in the 18th century.
Timber framing was already in decline when
these trees reached maturity. Scribing remained the
prevalent layout system until the disappearance of the
craft as it was known." Maybe scribing was forgotten, but it's hard to think they would replace the bowlegged Wild Man with straight timber on a historically significant building.

That's a German technique,

There are 2 primary schools of Fachwerk, as I understand it. One uses a lot of curvy, ornate bracing
The other uses a few straight braces. THe latter is common in Switzerland.

THe system used is still a scribe system, but not as involved as the French scribe where you have to individually map each joint. You scribe only timber locations, which accounts for any irregularity in straightness, but can't handle twist or inconsistent dimensions. As a result, timber frames were made only from good stock, cut to exact dimensions.

The joints can then be mapped mathematically. You trust that the timber at the joint is true to the required dimensions and lay out the joint using the edge of the timber as a reference. Joint mapping works like square rule, only omitting the step of cutting housings.

Scribing is not lost in Switzerland, it's still used by most. I was told straight out, you never trust even the best machined wood to be straight, you always will scribe it.

Swiss buildings are always made of old spruce and fir, be it 900 years ago or today. Really the forest situation is very similar to what it would have been in the Middle Ages (They never cut them down)

The Swiss way of taking car of a historically significant building is to take it down, take it apart, and put it back together in such a way as that you can barely even tell they did anything.

Got it and understood. Thanks.
I take it your back from warmer climes?
I'll be in touch soon about presenting at the Guild Conference in August.

Yup, back to cold and windy Indiana
It snowed today. I was sad.

Looking forward to hearing from you, if I can get away from these 10 hour days!

David -

Funny this, I am somewhat confused by half scribe systems and systems which require what I see as the tedium and burden of material prep. This in part because I've used timber from some of the best tuned sizers on the planet and have seen them fail to true up bow and wind, something Plumb Line takes care of easily without the delay or expense of materials prep.

I've also spent alot of thought on the probable influences that led to the development of Square Rule, and have worked to research its genesis.

I also have come across some very early oddities that hinted at glimmers of either mass production or gains / reductions, sparks in that development - A Sixteenth C. English barn (sadly sent over here on spec, but happily a huge influence on my career path) which had universal square mortises for the up end of the riven studs sized to the largest of the varied size studs, sort of square rule thinking in reverse - And a Seventeenth C. New Jersey Dutch barn (though not a NWD typology) which had counter hewing like flattings at most all timber ends to aid in scribing which were far deeper and refined than is the norm, which appeared almost reduction like in appearence -

Such refinements and thinking were I believe, part of what in time led to methods of universality and mass production and in time the great shift to square rule.

We're all still looking for our Rosetta Stone in this little mystery of who, where and when.

Will I should clarify,

Material prep is not here the result of half scribe, but rather vice versa. The half scribe system arises as a result of the high level of preparation that goes into the material because of the styling of the architecture.

The carpenters are not putting extra work into the frame to tediously prep the material so that it can be laid out with a half scribe system. They are tediously prepping the material because that's just their way. Because the architecture calls for extreme precision all around.

Tehn, since the material is extremely accurate, they need only use half scribe.

As to bow and twist,

first of all material selection is extremely picky. Second of all, timbers are small in cross section and shorter in length. This helps to minimize these concerns. But just to be sure, mortise faces are always cut square to the reference if they deviate.

Now keep in mind, I was taught that 1/16" is a large gap in a joint, the tolerance you cut to in a hidden joint.

AS to the development of square rule, I don't think we'll ever really know. It is likely, a lot of people came up with ideas along those lines over the centuries. The genius isn't often the one who comes up with something revolutionary and unprecedented, but one who puts old ideas together in a new way. I'd bet you a nickel that happened here. We're likely to find hints of square rule all over Europe. We don't know the half of the story, and so many little details get passed over. Swiss carpenters and architectural historians, for example, don't ever talk about layout because they don't think about it. It's just how it's done, that's all. There's likely to be a lot of little gems like this throughout Europe.

But if we really want to look for deeper influences, let's skip out from timber framing for a little bit and look at log building. Here we find something that applies the concepts of square rule, but for a different purpose completely. We have joints designed with normalized and reduced connections with timber reduced to a common dimension at these locations, but not to simplify layout -no these buildings even today are fully scribed- the technique here is used for the purpose of creating joints that retain their integrity as the walls move and settle, or as a means of connecting a number of horizontal logs or timbers into a single upright. Log ends fitted into a groove in a single upright need to be reduced to a common thickness.

But nonetheless if you didn't know about the problems of settling, movement, etc. and you looked at these joints, they would strike you as remarkably square-rule like. Food for thought.

I have a question about the so-called 'Mill Rule'
I have never used this method, so I don't really know how it works. My understanding is that here carpenters are using wood that is assumed to be generally accurate and straight, marking their joints along the timber believing that the edges are where they should theoretically be. This rather than using wood that is assumed to be inaccurate and marked according to a reference point -for example a chalk line or reference face.

But I would like to know some information as to how it works.

My Swiss associates have informed me, today they use a similar process in Switzerland, where the joints are often calculated rather than being laid out in a scribing floor and carefully marked (but this is the old method) But here, the timbers are very refined and planed to tolerances within 5mm. Any variation greater than that causes problems. To be safe, joints are all marked from a single point of reference -not a chalk line, but the truest face of the timber. So this is an edge rule technique.
Joints are not shouldered or reduced as in square rule. If a timber deviates excessively from the norm at a certain joint, the difference is accounted for by adjusting the length of an adjoining timber (that is to say, timber lengths are unique and therefore parts are not interchangeable)

My question is, how similar are 'Mill Rule' techniques as used in American shops.