Cantero: El arte del trabajo en piedra. Fotografía Luis Carlos González Fernández

The history of architecture has since its origins used wood and clay for its constructions. But stone has been the material that has given greater Nobility to its factories. It is what is known as stonework, a term that comes from the Latin cantus or piece. of stone from it also derive the words quarry, place from which the stone is extracted and stonemason, the man who works it. In other times, the guild of Stonemasons had a decisive importance and from its bosom the future architect would emerge among the initial tasks with which The Quarrymen face the task of separating the large blocks of stone from the living rock.

These are then transferred to the workshop to be squared or cut into smaller blocks for easier handling. The procedure used in both cases is the same. After marking the block that you want to cut along what is called the break line, some metal nails are carefully inserted into their boxes and then carefully hit with a mace and equally interspersed with blows on the sides of the stone to help it. To finally open, the block of stone yields obediently along the marked line in a surprisingly regular way. The stonemasonry workshops yesterday and today, animated by the continuous tapping of tools during working hours, bring together officers and apprentices under the direction of a master.

Everyone is attentive on the workbench to the stone they have to carve. In this case we will see roughing out a stone sar or parallelepiped, which is actually what is called the capable solid. From it a piece of certain complexity is taken out after eliminating We do not know the final shape of the excess material, but the officer glimpses it. From the first steps, first and always with a chisel with a sharp mouth that hits with a pot with a circular or bell section, the edges of the block are systematically lowered, leaving its edges alive. Bands of about 2 or 3 cm are refined as much as possible by checking their horizontality with a ruler or a simple wooden strip.

This simple operation allows the stonemason to find the line of the plane on each of the faces of the block, being able to eliminate from here more security the excess material for this, a chisel or a more powerful chisel is helped by its mouth and cut since the work is more extensive. Finally, when the level of the edges is reached, the stonemason begins to Lower this plane in a more Carefully avoiding warping, then with a bushing with replaceable heads to make the finish more or less fine, find the central part until its surface is completely flat.

Using the same procedure, prepare the different working faces, obtaining inclined planes when the piece does so. requires, as is the case, on this face some parallel lines are now drawn to distribute and extract the profiles of future concave and convex moldings separated by straight bands in such a way that the final profile of the piece will be mixtilinear as previously drawn. To do this, with a rigorous work order, the initial plans of each of the moldings are first obtained and on these, with a serrated jaw, the moldings are shaped with small strokes without separating the tool from the stone as the chosen piece. corner or angle outwards is necessary Draw the diagonal line in which the break occurs and proceed in the same way on the other side now there is the advantage of having the reference of one of its sides But on the other hand the meeting of the two planes must be perfect, so the stonemason with great confidence sharpens the cutting edge with the chisel because there is no room for the slightest error here.

These architectural elements occupy different places in the building, so the stonemason must resolve not only the corner angles. outwardly but also inwardly, this entails other types of difficulties that are resolved by the same procedure and with similar mastery while these workers continue working on friezes, cornices and all types of moldings with rigid planes and geometric profiles, other stonemasons in the workshop undertake another type of more delicate work and close to sculpture such as the carving of capitals, there is also a geometric base here in the initial approach, but the vegetal and free forms of a Corinthian capital for example force us to work with feeling, although without losing sight of the guide of the drawing on the stone classical architecture offers a varied series of capitals such as the Tuscan, the Roman Doric and the Ionic that offer fewer difficulties than the Roman order par excellence the Corinthian order its rich capital whose shape seems to be inspired by nature as Vitruvius states is characterized due to the presence of fleshy acanthus leaves that the master carefully outlines and hollows out with a gouge without forgetting the importance of drawing in this entire process, but where the art of stone cutting or stereotomy reaches its highest expression is in the solution of surfaces curves to form vaults, its casuistry is very wide but here we will follow the process of one of the most frequent and simple solutions, the so-called edge vault.

To build an arch or a vault, it is necessary to previously make the templates for each of its pieces, for which The said arch or vault is drawn with a compass on a plane with the same size as the built work will have, that is, at scale 1, the arch is drawn, lines are marked radially that mark the number of pieces or that make it up, as well as their length. That is to say, the breakdown of the arch and the cutting lines. This drawing is called a montea. All of these pieces are represented at natural size.

From this drawing, the definitive patterns or templates will be drawn that will guide the work of the stonemason. These patterns in Its constant use by stonemasons, the usual thing is to repeat the same drawing on a thin sheet of eyelet and subsequently cut out the shape of the voussoir. The next step consists of taking the template of the voussoir on the block of stone that we have previously called The solid capable In the piece that you want to obtain, the aforementioned template or end pattern is marked on one of its faces because it represents the front of the voussoir and its essential lines are extended on the lateral plane or joint plane.

The excess material is then eliminated, which It is called chiselling, doing it by a very common procedure that is known for theft of the chisel and the bell will then replace the heavy bushhammer with which its different faces are finished. Each of the novels has a specific function and shape within the Arch or the vault which means that there are several templates to use and the shape of each of them is different. In this case we see one of the novels that corresponds to the rooms of the vault, this is the piece in which two different planes meet. hence its greater complexity, although the procedure of its layout and carving are analogous to what has already been described, it is an angled voussoir.

The fundamental piece of any arch or vault is the one that closes this in its highest part, the so-called keystone and according to be the complexity of the vault, so will also be the complexity of its keystone. In the case of a groin vault formed by two vaults that intersect perpendicularly, the keystone will necessarily have the shape of a cross. This is the piece that the stonemason has begun to chip away at once marked on the the front of the stone block the corresponding templates, the same procedure is repeated again and the same tools previously described are used, leaving the final finished work to the bush hammer with its unmistakable grainy imprint once all the pieces of the vault that you want to build have been carved.

The help of a formwork is needed Generally made of wood that has a negative final shape of the vault in the formwork will be Apo voussoirs in strict order from the previous assembly that has been done on the ground of this reduced but real model the first The pieces to be placed are the salmer that mark the start of the vault on the walls where, as in the entire construction, a light mortar is used to help fix the stone. Afterwards, one of those that we have seen in work and that we have called an angled voussoir is placed. which responds to the interior edges and whose breakage is also noted from the outside so that it remains firmly seated, as many voussoirs are placed on its sides that are also received with mortar, observing how small wooden wedges are placed to maintain the levels and adjust.

All the pieces from here only go up the formwork. The pieces that respond to the diagonal edges, which is the living part of the factory, until the vault is closed with the cross-shaped keystone, their adjustment is essential for the stability of the vault. and the proper functioning of it, then the remaining voussoirs are placed until the vault is completed to finally remove the formwork, this is to remove the formwork so that the vault settles and enters into loads without any support from that moment on the weight and thrusts of the vault begins to work on the building, turning it into a living structure despite its inert appearance Oh