A pelorus is a navigational instrument resembling a mariner's compass used to take bearings relative to a ship. The first known use of the name for it was reportedly in 1854, the year that Lt. Friend of the Royal Navy applied for a patent for his version which he named the Pelorus, after Hannibal's pilot.
Similar devices had been used for centuries to take bearings of celestial objects to determine latitude. Newer versions of the pelorus use sighting vanes instead of the sighting telescope. See http://en.wikipedia.org/wiki/Pelorus_(instrument) for more information on how it's used.
Professor Brian E. S. Gunning of The Australian National University wrote about the origin of the name “Pelorus” in The Quest for Pelorus, September 2001, available at http://www.rscds-canberra.org/texts/Pelorus-30-7-06.pdf.
The owner of this piece contacted me after searching for “BH fecit” after finding it engraved on this pelorus. Ball Hughes, as an artist, frequently signed his works that way. Fecit is Latin for “he made it” and was formerly used after an artists name.
Description by the owner:
We know Ball Hughes made it because he said so! Of course it could be a fake or there was another “BH” who was an artist. Why would someone fake it and who else could have made it? Let's look at the piece itself for clues. It's ornately engraved and we know that Ball Hughes was also an engraver or coins and medallions.
The dedication says Dedicatua e (or de) Medici and the quadrant above says Alti Metra. I believe the translation of the phrases are: "Dedicated to de Medici" and "Altitude (height) Meter." I don't know if this refers to the House of Medici that was involved in trade for many centuries.
Closeup of bearing plate (azimuth circle)
The use of the pelorus is described in newer editions of The New American Practical Navigator by Nathaniel Bowditch. The first of many editions of Bowditch's book was in 1802 and it's not know if this version of the pelorus was invented yet. Bowditch died in Boston in 1838. In 1847, Ball Hughes created a statue of Bowditch with a sextant (another navigational instrument) next to him.
Usually a pelorus was mounted in a wooden box to make it portable for use anywhere on a ship. I assume it's made of bronze which is non-magnetic. Ball Hughes used foundries in Boston for casting his statutes in bronze. The seaport of Boston would have been a natural location for the manufacture of navigational instruments. I would guess it was made between 1840 and 1860 in Boston.
Closeup of sighting telescope and elevation indicator
Was Ball Hughes hired by a navigational instrument maker to engrave this pelorus? Was more than one fabricated? Was this a working instrument or a presentation copy. Who was it made for? How did it end up in an antique store? Was it made in Boston, in what year?
If you know anything about the Alti Metra by BH, please E-mail David Brown.
last update 9/10/2010
For noncommercial use, Copyright David E. Brown 2008-2010