JEAN VICTOR **PONCELET** (1788-1867), French mathematician and engineer, was born at Metz on the 1st of July 1788.

This work entitles **Poncelet** to rank as one of the greatest of those who took part in the development of the modern geometry of which G.

Bertrand, Eloge historique de **Poncelet** (Paris, 1875).

Between them the general theory of the complex variable, and of the various "infinite" processes of mathematical analysis, was established, while other mathematicians, such as **Poncelet**, Steiner, Lobatschewsky and von Staudt, were founding modern geometry, and Gauss inaugurated the differential geometry of surfaces.

**Poncelet** (1788-1867) and J.

**Poncelet** (1788-1867) invented a form of Prony brake which automatically adjusted its grip as µ changed, thereby maintaining F constant.

**Poncelet**, from which the work done during a given displacement could be read off directly.

In this effort he was as successful as were his great contemporaries **Poncelet** and J.

**Poncelet** throughout his work makes continual use of the foregoing theories of imaginaries and infinity, and also of the before-mentioned theory of reciprocal polars.

There was a reclamation as to priority by **Poncelet** in the Bulletin universel reprinted with remarks by Gergonne (Gerg.

**Poncelet**, how all problems of the second order can be solved by aid of the straight-edge alone without the use of compasses, as soon as one circle is given on the drawing-paper.