Very good boxwood and brass rule clinometer with compass in original case by James Parkes & Son c1850

The rule clinometer was, as described in WF Stanley’s 1890 publication Surveying and Levelling Instruments, an instrument “much used by civil engineers as a working tool” – designed for direct application to inclined surfaces to measure gradients, earthworks and natural slopes in the field. This earlier example, by James Parkes & Son, is a particularly well-engineered representative of the type, retaining its original leather case and all its working functions.

The Instrument
An antique combination rule clinometer by James Parkes & Son of 5 St Mary’s Row, Birmingham, circa 1850.
The instrument comprises a folding boxwood rule with brass fittings, incorporating two spirit levels and a magnetic compass. The compass is a 16-wind blued needle instrument suspended on a brass pivot, displaying cardinals, intercardinals and false points, as well as the James Parkes ‘eye’ trademark. The hinge arc is graduated in degrees 0°-90° and also displays the ‘eye’ trademark.
On the compass side of the body, an engraved table gives lengths in inches for a one inch rise against degrees, allowing rapid gradient calculation in the field. A scale of twelve inches, when fully unfolded, divided to eighths runs along the reverse; the bottom edge carries a further twelve inch scale divided by both tenths and eighths. The two arms of the rule each contain a brass bubble spirit level.
Presented in its original leather covered case with purple silk and velvet lining and swinging catch.

James Parkes & Son
James Parkes found his company in 1839 at 5 St Mary’s Row in Birmingham. Originally known for manufacturing measuring tapes, mathematical instruments and compasses, the company was renamed James Parkes & Son in 1845 and expanded into microscopes.
In the Victorian trade, scientific instrument makers such as Parkes were the primary source of precision instruments of all kinds for professional, military and civil engineering use.

Condition
The brass retains much of its original lacquer; the boxwood shows no cracks. The compass finds north easily. The spirit levels are functional. Some signs of use throughout, consistent with a working professional instrument, but in excellent condition. The original leather case is sound, with some losses to the covering at the edges and verso; the silk and velvet linings are bright and undamaged.

Why This Piece?
A complete, working rule clinometer in its original case is a fully functional piece of Victorian civil engineering history, and examples by James Parkes & Son are very scarce.

A wonderful gift for: a collector of Victorian scientific or surveying instruments, a retirement for someone with a connection to civil engineering, surveying or construction, or a birthday or anniversary for someone who appreciates the ingenuity of Victorian professional instrumentation.