The Centrolinead, a draughtsman's instrument invented by British engineer, architect and mathematician, Peter Nicholson (1765–1844)
Thomas Bradley; Peter Nicholson
Illustration from the book "Practical Geometry" (<a rel="nofollow" class="external free" href="https://books.google.com/books?id=FetJAAAAMAAJ&amp;pg=PA42">https://books.google.com/books?id=FetJAAAAMAAJ&amp;pg=PA42</a>)