The title of the book is “Logometron architecturae militaris Freitagianae” and means “Art Measure of Friday Fortification. The book was published by the author Andreas Alexander in 1665.

Andreas Alexander was an Italian architect in the 17th century. The book is a very rare work on the circle sector. At the beginning he introduces us to the history of the circle sector. This is followed by a tribute to Galilieo Galilei.

He begins first with a description of the scales and tables of the instrument and the elementary operations that the circle sector can perform. The circle sector is a partial area of the circle formed by an arc of the circle and two lines adjacent to it to the centre.

After explaining the most important basic elements, he goes on to list some simple arithmetic problems. Step by step, the problems become more complex. At the end he introduces the military fortification and its geometry as well as its measurement.

The book is of a handy size. It is about the size of an A5 sheet. The hard dust jacket has a washed out greenish colour. The book has two different types of pages. The text pages are slightly thicker than the drawing pages and the colour is slightly more yellowish.

The book has 94 pages. At the end of the book there is an appendix. In this appendix you will find many illustrations that belong to the book. The illustrations are geometric and precisely drawn. In the book itself there are some tables with figures, but no sketches or other illustrations.

The book has a wonderful layout. Nevertheless, it has no table of contents. Instead, it is divided into different chapters. The title of the chapter is always given at the top centre margin of the page. The page numbers are also noted.

Denise Gerber, 21-932-363