H.S. Crabtree

H.S Crabtree

Toronto

Brass hinges

 

The rule is entirely brass and is in perfect condition albiet some tarnishing 

The rule is heavy and sharp in order to achive accuracy when drawing on graph paper

H.S. Crabtree had a comfortable relationship with the Ontario government.  Records from the Dept. of Northern Affairs and the Dept. of Highways show numerous purchases of Crabtree items including; blueprint paper, mathematical equiptment, and survey tools.

(archive.org)

A parallel rule made by British business H. Hughes & Son circa 1920.  It remains the only other ruler with this particular hinge design.  Since Canadian makers often sourced already-made products and resold them in their region, it is entirely possible that H.S. Crabtree imported parts or designs from H. Hughes & Son to sell in the Canadian market.

(americanhistory.si.edu)

 

This Parallel Line Rule is a heavy-weighted object, suitable for use on flat surfaces. It was as drafting tool used by surveyors, map makers and navigators.

It was made by H.S. Crabtree around 1930, and was eventually collected by famed Canadian surveyor Louis Sebert who collected older, non-technical objects for nostalgic purposes. In 2003 Sebert's wife handed the instrument to the Museum of Science and Technology in Ottawa where it has been ever since

H.S Crabtree established his business in Toronto in 1928.  

He sold an array of products, many of which were useful to surveyors.  This maker was lucky enough to have a close relationship with the Ontario government that purchased many products from Crabtree.  However, the 1930's depression must have been tough on this Toronto maker.  

Apart from government purchases it seems as though Crabtree's business did not expand outside of Ontario and he remains a relatively unknown maker.  

H.S Crabtree's Toronto business dissolved in 1980, fifty-two years after it was first established.

These four photos show the dimensions of the instrument itself.

To the left are captured images of relevant information and objects.