Saturday, January 28, 2012

Leonhard Zubler's Nova Instrumentum Geometricum



Leonhard Zubler wrote Nova Instrumentum Geometricum in 1607. Zubler (d. 1611) was a Swiss goldsmith and instrument maker. He is credited with introducing the use of the plane table into modern surveying. This book demonstrates and promotes the use of his instruments in techniques of triangulation. Many of the situations depicted concern warfare. Note the two surveyors flanking the title page, proudly holding their measuring instruments.


The image above is page 23 of Zubler’s Instrumentum and demonstrates a triangulation technique for obtaining the distance to a fortress.


Leonhard Zubler's Nova Instrumentum Geometricum 



Saturday, January 21, 2012

Desargues' Sundials





Girard Desargues (1591—1650) was a French mathematician and engineer best known for his contributions to projective geometry. He published materials on many technical and engineering topics. In 1640, he published a tract on dialing-constructing sun dials. This is the title page of the 1659 English language translation of this work.


Desargues' Sundials

Sunday, January 15, 2012

Kepler's Logarithms


This is the title page of Johannes Kepler’s (1571—1630) Chilias Logarithmoria, 1624, logarithmic tables he constructed by geometric procedures. Kepler also gave a proof of why logarithms worked and then used them extensively in his calculations of the Rudolphine astronomical tables.


Kepler's Logarithms

Saturday, January 7, 2012

Johann Kepler's Uralten Messekunst Archimedes

Johannes Kepler ( 1571—1630 ) was concerned that Austrian wine merchants were cheating their customers by gauging the volume of their barrels incorrectly. To correct the situation, he undertook a study of the volume of wine barrels. He published his findings, Nova Stereometria Doliorum vinarorum, in 1615. Forsaking classical techniques of volume calculation, Kepler produced solids of revolution, dissected them into an infinite number of circular laminae and obtained a volume summation. He applied this technique to consider solids other than wine barrels; in total studying the volumes of 92 different solids. Written in Latin this work was scholarly and had a limited audience. In order to increase his financial returns in 1616, he published a popular German language version of his work, Ausszag aus der Uralten Messekunst Archimedes. The page images are from the Messekunst. Page 27 contains a discussion on the volume of a torus. Page 28 returns to a consideration of the volume of wine barrels.

Johann Kepler's Uralten Messekunst Archimedes