Leonardo da Vinci

It is impossible to discuss a history of architectural sketches without an example from Leonardo da Vinci, whose numerous sketchbooks reveal the genius of an architect, painter, sculptor, and inventor.
Although he built or finished very little architectural work, he proposed designs for domed, centrally planned churches, fortifications, numerous mechanical inventions, and buildings in various scales from chapels to palaces to cities. At an early age he started in the workshop of painter Andrea del Verrochio. Throughout his career, Leonardo worked as a military engineer in Milan, in his own studio in Florence, and later in his life, on projects for King Louis XII in France. It was in Amboise, France, where he died in 1519. His works that remain include extensive sketchbooks, some sculpture, and paintings such as the Mona Lisa, Virgin of the Rocks and the fresco The Last Supper in San Maria delle Grazie, Milan.

A consummate observer, Leonardo took an empirical approach to satisfy his curiosity about the nature of the world, giving him the ability of ‘sight and insight’ ( Janson, 1970). He felt that experience is acquired by the senses and, subsequently, that seeing involved an active process. Feeling a need to represent nature as he viewed it, his approach was opposed to that of universal beauty as discussed by Alberti. He viewed vision as the source of scientific truth (Barasch, 1999).
In 1487 Leonardo produced a model for the design of the dome of the Milan Cathedral. This page from his ketchbook, Codex Atlanticus (Figure 1.2), presents some of the design process for the tiburio of this cathedral. It shows the stacking of bricks or blocks to structure the light arches and buttresses. Typical of Leonardo’s sketches, it is possible to view details of construction and connection, as the blocks are rendered with interlocking notches. As a design study, the sketch also displays
rough beginnings and alterations, showing a centerline and horizontals to guide proportions. Only half of the construction has been detailed; Leonardo understood enough to move on to another drawing or a model. Perhaps he rejected how the proposal was progressing, or the sketch had simply served its purpose and  ould be set aside.
This page has numerous identical stippling marks as the  recto. These marks were  resumably used as guidelines and also acted as identical templates to explore multiple variations for assembly and construction. The marks are in fact pinpricks that resemble the pounced guidelines of a cartoon used to transfer a design onto a fresco. Leonardo was well aware of the transfer techniques of cartoons using bilateral symmetry. It is evident that on other sheets from the Codex Atlanticus, he folded the paper to prick guidelines through both sides of the paper to perceive a symmetrical whole (Bambach, 1999). Evidence of a similar technique can be viewed on this page; a prominent crease down the center. The irregular spacing of the marks coincides exactly, strongly suggesting that at least part of each sketch was pricked simultaneously, or possibly, the pages were first folded and then pricked through all layers.1 This points to an economy, in that Leonardo would not need to recalculate the tiburio, but make minor alterations to the structural form or the stacking of the blocks on identical sheets. In this way, one can view the architect/builder concerned with the solidity of the structure as well as the artist, utilizing known transfer techniques.

Donato Bramante (1444–1514)

Bramante was one of the first of the great High Renaissance architects, influencing numerous
prominent architects of Rome such as Peruzzi and Sangallo. He is best known for reviving the architecture
of classical antiquity, which had begun with the works of Alberti (Allsopp, 1959). Vasari
reported that Bramante spent much of his time studying and sketching the buildings in Rome (Vasari, 1907).

Born Donato di Angelo di Anthonio da Urbino/Pascuccio, it is speculated that he studied with
Piero della Francesca and/or Andrea Mantegna. His first notable building was S. Maria Presso S.
Satiro in Milan. In Rome, some of Bramante’s most celebrated and influential projects were for
Pope Julius at the Vatican, where he designed the Cortile di S. Damaso and the Cortile del
Belvedere. With an interest in centrally planned churches similar to Leonardo, he also designed a
Greek cross plan for St. Peter’s with a vast central dome. His expressive building of the classical tradition
was the Tempietto of S. Pietro in Montorio, 1502.

Bramante’s design for the Tempietto was sited in the courtyard of the Church and Monastery of
San Pietro in Montorio. It constitutes a diminutive temple acting as a Martyria, standing on the place
presumed to be St. Peter’s Martyrdom. Small and circular, it revisits antique forms appealing to contemporary Christians’ preferences, crowned with a hemispherical dome resembling the Pantheon.
This small monument displays simple proportions where the width of the dome is equal to the height
of the interior cylinder (Allsopp, 1959).

The sketch above exhibits a small shrine-like structure, representing an example of a centrally planned building. The sketch reads as an elevation of an octagon-shaped dome on a raised foundation. In plan, the building presented appears to be shaped in the form of a cross with small projections containing porches; it is vaguely reminiscent of Palladio’s Villa Rotunda.

Bramante’s concern with the reference to a shrine led him to draw this sketch demonstrating its volume
from the exterior, rather than interior space. Here, he used the porch to accent the central
domed space, stressing the qualities of a monument, a temple from antiquity.
The building’s organization describes an octagon within a Greek cross imposed within a square,
but the sketch presents an image somewhere between a perspective and an elevation, as the face of
the porch has been drawn slightly taller than the side porches. To stress the central altar and promote
a three-dimensional effect, Bramante employs shading on the side of the octagon, further confusing
the flat façade of the elevation. The sculptural figures on the roof have been drawn with the same lack
of complexity as the scale figures standing on the stairs. Although the sketch does not appear to be
hurried, Bramante describes the stairs with minimal detail. The set on the left display some definition,
while the other set of stairs have been represented simply by double diagonal lines. This technique
concentrates the focus to the center, and emphasizes the fact that the building was designed to
be viewed equally well from all angles.

The sketch suggests a self-reflexivity, as it refers to the many centrally planned structures designed
by Bramante. It also recalls the three-dimensional/volumetric qualities of Bramante’s concern for a
building’s mass. The architectural historian James Ackerman wrote about the volume of Bramante’s
walls: ‘[W]e sense that where the earlier architect drew buildings, Bramante modelled them’ (1961,
p. 27). Although this design for a small building may not be directly related to the Tempietto, it is representative of a theme, one that Bram ante explored throughout his career.