Stair-building and the steel square — Key Ideas to Explore

Tangents and Face-Moulds as the Core Method

The excerpts repeatedly return to tangents and face-moulds for laying out wreaths. For example, the text explains that “the tangents as here presented are those of the elevation, not of the face-mould,” and shows how to derive the angle between tangents using dividers and perpendicular lines. A typical procedure: draw a baseline, measure tangent lengths from a diagram, erect a perpendicular, and swing an arc to find the mould’s angle. The joints are then squared to these tangents.

This approach is applied to both bottom and top wreaths, with separate figures for each. The language is procedural: “Make the joint at h square to 2-h, and at a″ square to a″-2.” Readers must follow the figure references closely—the text assumes you are looking at the diagrams while reading.

Well-Holes and Curved Turns in Practice

A well-hole at the upper landing introduces a new challenge: two wreaths must be jointed, requiring “the same inclination” over the crown tangents. The text shows how to fix tangents b″ and c″ to achieve this. Similarly, curved turns at the bottom of a stair are handled with a plan of curved steps and stringers (Fig. 100).

The authors stress that the diagram must be drawn full size in practical work. This emphasis on full-scale layout reinforces the manual’s workshop orientation. The excerpts do not cover every stair type, but the pattern is clear: each configuration demands a custom tangent diagram.

The Pitch-Board and Proportion of Risers

Early in Part I, the book introduces the pitch-board as a tool for setting out stairs. The contents list includes “Pitch-board” and “Arrangement of risers,” though the excerpts do not detail these sections. However, the introduction mentions “the proper proportions of rise and width of tread” as a key problem. This suggests that the manual balances geometric layout with ergonomic rules of thumb.

Readers should note that the excerpts are weighted toward wreath construction; the pitch-board and riser proportion sections may appear later in the full text. The book’s structure implies a logical progression from basic definitions to complex curved work.

Steel Square Applications Beyond Stairs

Part II, by Morris Williams, covers the steel square’s use in roof framing and other construction. The contents list mentions “Miter and length of side of polygon” and “Heel cut of common” rafters. Although the excerpts do not include Part II text, the introduction states it contains “many applications of this useful instrument to roof and other types of construction.”

This pairing suggests the steel square is presented as a versatile layout tool, not limited to stair work. Readers interested in general carpentry geometry may find Part II equally valuable. The book’s dual authorship also means two distinct voices and approaches within one volume.

This manual rewards careful, diagram-in-hand reading. The excerpts show that the authors assume a reader who can visualize three-dimensional geometry from two-dimensional plans. If you are new to stair-building, start with the pitch-board and riser proportion sections before tackling wreaths. For experienced carpenters, the tangent method for face-moulds offers a systematic alternative to trial-and-error layout.

There’s something honest about old manuals—the way they trust the hands more than the theory. Reading the stair-building one, I kept thinking of another quiet book, Asbestos, Its production and use With some account of the asbestos mines of Canada — A Reader’s Guide, how both linger on what work actually takes, not just what’s claimed. Those pitch-boards and mine shafts stay with you.