The Sienese artist-engineer Mariano Taccola left behind five books of annotated drawings, presently in the collections of the state libraries of Florence and Munich. Taccola was well known in Siena, and his drawings were studied and copied by artists of the period, probably serving as models for Leonardo da Vinci's notebooks. However, his work has received little attention from scholars and students in recent times. The author, a sculptor, has long been interested in Taccola's drawings for his studio projects. Although Taccola lacked the fine drawing hand displayed by many of his contemporaries, his inventive work may appeal especially to viewers today. Based on examination of the original drawings, the author discusses the qualities that make Taccola's drawings unique and considers what Taccola's intentions may have been in making them.

The philosophical and theological content of a masterpiece of Old Russian icon-painting—Andrey Rublyov's Trinity is regarded in the light of its geometry. The aspects under study are the geometrical properties of the rectangle of the Trinity (which generate a sequence of circumferences related by the golden proportion) and also some of the peculiarities in the composition of the icon. The roles of the circle, the octagon and inverse perspective in the Trinity are discussed. The author establishes correspondence between the theological triad Revelation—Illumination Transformation, which makes up the fundamental content of the Trinity, and the mirror and dynamic symmetries of the icon.

Experiments in ship camouflage during World War I were necessitated by the inordinate success of German submarines (called “U-boats”) in destroying Allied ships. Because it is impossible to make a ship invisible at sea, Norman Wilkinson, Everett L. Warner and other artists devised methods of course distortion in which high-contrast, unrelated shapes were painted on a ship's surface, thereby confusing the periscope view of the submarine gunner.