Langlois Graphometer - Circa 1730

About the Item

This is a BEAUTIFUL Graphometer made by the premier instrument maker in France, Claude Langlois, after Bion and Butterfield had stopped making instruments. As discussed on my Graphometer - Semicircle webpage, the French produced a good number of Graphometers from 1600 to about 1850. And a fair number of these Graphometers are still around. If you want to add a really nice Graphometer to your collection, this Langlois merits serious consideration for these reasons: 1. While not as well-known internationally as Bion and Butterfield, Langlois was The Man in France after Bion and Butterfield had passed away. 2. The President of Harvard College in the mid 1700's owned a Bion Graphometer and used it to survey around Harvard. This makes for a nice story if you display a French Graphometer from the same time period. 3. This Graphometer has a wonderful design and exhibits a very high level of engraving skill, especially when considering that Langlois made this Graphometer pretty early in his career. 4. An instrument with transversals - the concentric circles - adds a lot of eye-appeal and interest to early instruments in my opinion. In theory a surveyor could read angles to six minutes of a degree with this Langlois Graphometer. As Norwood pointed out at page 80 et seq. in his 1639 book on Fortifications, the mathematics behind the concentric circles and diagonals approach were fairly complicated, with many makers likely missing the mark. Over time most makers opted to use a vernier system instead of the concentric circle and diagonals system. Again, this makes for a really neat story if you display this Langlois Graphometer. I love the look of this Graphometer - wonderfully skilled engraving matched with the concentric circles transversal. This Graphometer was done by a young Claude Langlois, and shows why Langlois rose to prominence in France so quickly. Keywords: Surveyor, Surveying, Theodolite, Transit, Circumferentor, Semicircle, Level, Graphometer, Graphometre, Teodolite, Arpenteur

Dimensions:

Height: 8 in (20.32 cm)Width: 13 in (33.02 cm)Depth: 8 in (20.32 cm)

Materials and Techniques:

Brass

Place of Origin:

France

Period:

Early 18th Century

Date of Manufacture:

Circa 1730

Condition:

Refinished. Wear consistent with age and use. A lovely graphometer - will make a for a really nice display - wood stand not included.