Hi Will,
I read through the copy of Timber Frame Joinery and Design Volume 2 and can understand your impression. My initial takeaway is that I find some of the nomenclature surrounding square rule to be inconsistent and unsatisfactory.
For example, as you cited, the article by Anderson from Dec. 92 describes the Japanese approach as "the center line square rule method". However, the very definition of square rule in "Introduction to Layout" is as follows "The square rule was developed in North America, apparently near the turn of the 19th century (the earliest dated example is 1803). Timber framers could now get roughly squared timbers relatively easily. The trees here were large and could be milled or hewn down to a nearly consistent section along the length without concern for wasting too much of the tree, and surfaces were true and straight enough to serve as reference." I feel that the above definition is pretty much the stock basic definition of square rule as far as I have encountered and I think that most people would be familiar with, with notable emphasis to North American development as well as the edge as primary and preferred reference face. The eastern systems of layout clearly predate and are are on a totally separate line of development from anything North American, so I think that we are setting up for a lot of confusion in trying to refer to the two as being part of the same basic system.
I know that there are techniques for snapping lines in square rule (and scribe rule as well!) but I would argue that these are not central to the layout method in the way that a centered snap line is central in Eastern layout. Edge reference is the norm and the gold standard in square rule, snapping lines typically seems to be a way to manage unusual or undesirable situations in practice. Square rule has a mindset that revolves around the edge of the timber, as is seen in the practice of offsetting tenons a given distance from the edge. The same article by Anderson speaks to the centrality of the snapped center line to Japanese layout. “Generally, the carpenter uses four different classes of lines to lay out
his work. These are the shinzumi,suihezumi (or mizu), tatezumi and the yorizumi.”...”Shinzumi can be read as “center line” but a different reading of the Chinese characters is “true line”, which comes closer to how the mark is actually regarded while constructing the rest of the house”. In the end, I think that the designation of square rule regarding Eastern practice is inadequate to describe a system so different from what most people would readily recognize as “square rule”. Eastern layout systems have their own very definite, developed, and distinct history, practice, tooling, and philosophy. Surely they deserve the recognition of those distinctions to be acknowledged by the nomenclature used in reference.

Right.
I'm always learning something new in this craft, and I've expanded my interpretation of square rule since I wrote that "Introduction to layout" article to include snap line square rule. As long as we are getting good results and understand the methods to get there, the definitions, while confusing now, can best be clarified by discussions such as this.
The distinction for me (and maybe only me) remains either bringing the joinery shoulders to match an irregular surface (scribing) or bringing it into a housing that is referenced off a snap line, centered or otherwise (square rule). Can you provide an example of how the traditional eastern methods are different from either of those? This might be worthy of an article in Timber Framing.

Hi Sean,

Glad you kept up with this...I'm not able to get to some of my literary resources at the moment...

Great post, and I agree with your evaluation of this. I think (too often) here in the West many only focus on Japanese systems of Line Layout, and thus perhaps misinterprets the translations. Much can be lost in any translation, and seldom (if ever?) takes in Japan's own regional differences within the applications of line rule from Temple work, to folk styles of Minka construction...all the way to the Boat building traditions that also employ Line Rule. None of this (which you and I have discussed) even begins to scratch at the surface of...Line Rule...in the historical context which is much older in application than just the Japanese traditions.

Your post begins well to reflect this and the differences and broadness of the topic.

Hello Will,

I could not agree more that this topic is worthy of an article for our TFG journal. Perhaps exploring the different methods historically and/or application modalities. I have started a rough outline a few months ago because of our discussions here. I would love editorial feedback and perhaps a direct conversation at some point if your willing. I really do want to get back to some of my old Library haunts to refresh some of my understanding of the original contexts to this subject as points of literary reference.

I think the fact that we have only seen timber framing grow in popularity since the 70's, with many learning something new along the way, we are also going to see an expansion of ideas about it. Now with even more growth among younger practitioners we are seeing a melting pot of methods and interpretations of all manner of method and layout systems. With the Internet allowing exchanges, not only amongst ourselves, but also collegues in other cultures, this understanding will further expand I am sure, This interpretation will not only expand of recent layout methods (respectfully) such as Square Rule (being less than 300 years old) but also of the more acient methods like Scribe and Line Rule.

I further agree that good results and understanding (for ourselves) in how we arrive at our individual timber framing goals is the most important thing for each of us. It reflects the contemporary dedication to craft we all want to achieve in our give works within the craft.

I do not think (at all) you are alone in your distinctions or interpretations of current understandings within modern Western Layout Methods. I find your view(s) generally common among many in our craft today. This is a rather logical understanding (I think?) within a limited and small (relatively) normative culture such as our...North American Timberwright population. We (collectively) are limited to a very small selection of publications with a very narrow scope of exposure to the craft. This has expanded (greatly!) in the last decade with the internet, and other contemporary publications on the subject now coming to us in other languages and traditions. With this literary and technological advancement, we find ourselves in conversations such as this.

I like parts of your break down of the different Layout Systems. However I do believe they are too overly simplified and/or too interpretive (subjective?) and not reflective at all of the actual parts and/or applications of the give marking systems as they originated, evolved and are still applied today.

We can agree that...Scribe Rule...(in its most basic of understanding) is a matter of fitting one unique plane (or edge just as a shoulder in a joint) of reference into conformity with another. This is the way of it, be it stone, textiles, or wood. Especially in the bespoke aspects of the craft(s).

The other aspect of creating a...generic uniformity within a joint matrix..is by all means an aspect of...Square Rule. This was the entire foundational purpose of how this system evolved, being able to take roughly shaped (hewn or sawn) stock material and creating...generic uniformity...within the joint matrix of a timber frames design...be it for architecture or a ship. This was done (as Sean referenced above) off a reference plane and/or edge of a timber...with no other point of reference ever required, or part of the system. Snapped lines had no part of the original Square Rule marking and layout system. I have never seen, or read a reference (historically) to snapped lines being part of the system or how to understand its application and execution. The addition of snapped referenced lines has only been found in the most recent of contemporary timber frame layout systems as they have evolved in individual application from the melding of Line and Edge (aka Square Rule) into one amalgamated system. This is a reinvention in the coeval designs of timber frames today here in North America, and not of original context of modality.

As I offered earlier in above posts...Line Rule...has nothing to do with...Square Rule...in the historic context, nor (for the most part) with a...Framing Square....as we understand them here in the West. Line Rule (Japanese, Korean, Chinese, et al) is a system that has both scribed elements within it, and works on structural members that are very often round or organic in nature...so a square has little use quite often...as we understand their application within Square Rule.

As for a specific difference..."of how the traditional eastern methods are different...."...I'm not sure I could illustrate that more than I have thus far in context application of the three systems? I guess (??) I could offer another breakdown of the three systems from both the historic application and how they are still used (in their pure form) today, and perhaps for publication purposes expand illustrations of the different systems for clarity.

Scribe Rule...has a wealth and depth of technique depending on cultural evolution of the given system. From overlays of framing members (timbers), use of lofting planes both below (floor) and side (walls) in some systems, to the application of plummet tools/systems, and even some templating as it latter began to evolve into the next oldest system...Line Rule.

Line Rule...has almost (from what I can glean thus far) as old a history as the different Scribing systems. Lining system also have a deep and vast application of modalities within it depending on the cultures that apply it. Line Rule also has, or does have, aspects of Scribing within it as much (most??) of it is performed on organic shapes...and...does not have to rely on a Framing Square as we understand (and use it) here in the West.

Square Rule...historically in application (and as it was taught until recently to most Timberwrights) is solely dependent on the use of the...Framing Square...as we know it in the Western context. This is even reflected in the shape of the tool's two arms. The tools blade and tongue are sized according to equivalents to the most common standards in mortise and tenon proportions most common in Western timber frames. The Edge Rule (aka Square Rule) system was entirely dependant on this tool, and the referenced edge/plane of a given timber to be jointed...No other tools of layout are required to execute the marking of a given timber frame, other than perhaps dividers or story pole, and marking tools such as a Scribe Knife and/or Pencil, and for the better equipped Timberwrights a Race Knife.

I wouldn't say that Eastern timber framing in general uses housings in the same way that western square rule does. Many times there seems to be an emphasis on stock preparation making reduction housings unnecessary. Anderson's Sumitsuke 1 seems to also refer to some use of mapping as well "While marking these, memos can be noted on the ezuita regarding irregularities in dimension, height variation, local adjustments, etc." What I don't know is how this changes over the various forms (Minka vs. temple carpentry for instance in Japan). I would love to hear from some people that specialize in Eastern practice such as Chris Hall or Jay on the usage or lack of usage of reduction housings in traditional Japanese framing.

Hello Sean,

In general, across the different systems of Line Rule marking methods in the different cultures that still routinely employ them (especially in the folk classes of the architecture within these culture) there is little in the way of...Reduction Housing...as understood in the Western timber framing context to a uniform size, location or even shape in some examples. Again, in the classic sense of the method...Line Layout snapped ink lines represent a point of internal registration within a given geometry of a timber that may even (as found in many Minka) have different elevations of reference along the often turning and twistings of a live edge beam. The housing are either plotted in the detail on the plan and elevation view or story poled to correspond to these reference points, and/or scribe templated to conform to the unique characteristics of each joint intersection. This was (and is) one of the key areas of interest to me in learning how this was/is achieved. Unlike European scribing methods, with the timbers ever needing to be referenced to one another, or lofted by plummet in any way, the Eastern approach rather only needs the understanding of the Line Rule modalities themselves, templates, story poles, strategic plan and elevation line drawings to do the brunt of this very complicated and often organic fitting of bespoke joint intersections. In other context of this system, items are (very much) uniform in nature, yet organic and/or rounded in shape.

If a reduction to a uniform shape (or depth) is performed it may only apply to a individual joint within a frame. Each organic shape being reduced to a more consistent and uniform geometry for a given joint intersection.

Sorry Sean,

I completely neglect to address the..."stock removal"...you referenced.

This to, also seems to be either misunderstood, and/or misinterpreted by many as being for dimensional shaping and or gaining uniformity within the timber...which is the furthest from the truth both in Folk Class and Imperial or Merchant Class Japanese architecture, and I don't know of a single case of it being so in the Korean or Chinese modalities...(not to say it couldn't have take place in some limited or regionally specific aspect?)

Stock Removal is for the soul (and it would seem almost entire goal) of aesthetics and surface treatment against water and dirt absorption. Planned timbers have there grain closed (for lack of a better discription) against water and dirt and seem to present as more durable surface for untreated/finished timbers, than rough unplanned surfaces...especially with the fine edges achieved in Japanese Kana blades and what they leave behind for a finish. Many joints do have housings and these are taken off the Line for reference, not an edge or plain of a timber. To this reference, in the more refined classes of Japanese archtiecture, these housings will follow some common format to a given region and/or Daiku, yet again the timber itself may be out of square or organic in some other context, and it hasn't been until recent times (and the onslaught of modern tools and Western influences there post WWII) that more attention to...Squareness...seems to have become of more focus among some practitioners.

In many ways (some regrettably) the West has influence Japan more than they have us. As a culture of paradoxes in many ways, after their suppression in post WWII culture...all things old where considered worthy of abandonment by many. Old was bad, and new (being mainly Western) was good. It has not been until very recently that we see a resurgence of Cultural pride and desire to save what has almost been lost within many folk arts and crafts. Parts of the countryside have virtually become devoid of growth, until very recently, with most opting for the newness of large cities.

Korea's and China's...stock preparation...also is focused almost entirely on aesthetics and not necessarily the detail refinement of geometry to a set homogeneous shape...per se.

Here is a nice short post to balance out the thread.

Some housing are great to carry extra loads, so even if you are matching a surface to another there are times when a housing is nice.

Timbeal,
A good point made for clarification. Every variant of layout uses structural housings for load bearing purposes. Sizing housings for reduction are something seen most frequently on square ruled frames.


Jay,
I would have to disagree that snapped lines were never part of square rule historically. I have a reprint of "Timber Framing Made Easy" by Fred Hodgson published in 1909 which references an offset snapped line technique in dealing with out of wind timber. This is presented as one possible way to deal with twist. The context being that laying out purely from the edge is preferred.

Thanks for clarifying some of that Jay. So would it be fair to say that in most Eastern frames similar components are less interchangeable that in a typical square ruled frame?