Gunner's Protractor
 

Hi all, I bought this over the weekend at a local gun show but aside from knowing what it is, I have no idea as to age or what country it was used by. I suspect it English in manufacture, it has the name W. Deane on it and I am familiar with the English gun manufacturer Deane, Adams and Deane so I purchased it, thinking that maybe at one time the company made scientific instruments as well a sporting guns.

The protractor is used to determine the caliber of cannons and shot but there is a host of other scales and mathematical functions on the scales and I hope one of our European brothers can add some insights to my recent purchase.

I think these are reproduced for the US Civil War reinactor crowd but I'm pretty sure this is an old protractor.

Regards,

Greg

Oh Man, i love this device; it's rather appealing, with its scientifical look.
Have you been here, Greg :
http://www.bonhams.com/auctions/14627/lot/359/
From here i'd say yours is a genuine Dean example.
Did you look at the prices ? :eek:

Fernando, thanks for the FAST reply. The price !!!!! WOW!! :D I Goggled for some time and came up with minimal useful links, I didn't think to look at the auction houses.

Geg

Don't mention it ... brother ;)

Spectacular piece! Not only for its weapons appeal, but scientific as well! i just sold an 18th c. graphometer that I'm sick over ( :( ), but bills are bills. I think pieces like this highlight a collection, even if they are not strictly arms/armor. Sometimes, it is the 'acutrements' that help highlight a collection! Hey, perhaps I'll start another thread with some such pieces...

Just get started, Capitão :cool:

I think it has a chart that tells you the density of certain items per square inch.. like seawater.
In the european chart this would be 1,024 cm3 . ;)

the other numbers.. maybe some sort of way to calibrate your sights, but i never saw something like this before.

Guys, the person in question is William Deane (first half 18th century) ... and apparently not from the Deane & Dean gun traders family.
He was an expert in precision devices, like gunner's calipers and other.
The following id the description of a device of one of those:

A brass pair of William Deane gunner's callipers, English, first half 18th century, signed William Deane Fecit, the callipers with inset steel points slide over each other to allow both internal and external measurements to be taken, the upper face with geometrical shapes, scales of quantity measures, proof and service, and sector scales 0-100 the reverse with scales for 'cubic feet of metal &c in pounds and Decimals Adverdupois & Inches of ye same in Ounces and Decimals 12inch linear scale, size and weight of guns scale. The hinge with direct reading scales for the width of the opening in inches and degrees together with a 19th century 6-inch ivory yellowed sector., length closed 15.2cm 6in

Hi all, I think mine is in better condition, especially when I look at the hinge; which looks damaged in the auction item.

The age is very exciting to me, the mid 1700s - Napoleon and his wars, on land or sea, just imagine if this caliper could talk!

There is verdigris and something crusty on the calipers, what are your thoughts on gently cleaning this off?

Greg

Hi all, I found additional information on a different Forum, I've attached the relevant information and the link to the source.

"Although gunner's calipers of the continental pattern were known in England through Stone's edition of Bion's book on mathematical instruments (catalogue no. 32), English-made calipers had already settled on a distinctive design. Their two flat blades are hinged so that they slide freely over each other, permitting the steel tips to point either inwards to take the diameters of shot or outwards to measure the bore of a gun. In this example, scales at the hinge give diameters in inches and the corresponding weight of iron shot. The scales for inches of the bore and for the pounder rating of the gun are engraved along the length of one of the limbs. The remaining space on the limbs is occupied with tables of specific weights and quantities of powder for iron and brass guns, as well as a sectoral scale of lines and a series of diagrams representing proportional relationships between different planes and solids."

http://www.mhs.ox.ac.uk/geometry/cat10.htm

Greg

Some collectors regard "cleaning" as a capital offense.

... and this is a criterion worth the maximum respect !

I totally agree.

Greg