PRESENTED is a late 18th C. mariner's octant made by the two famous Troughton brothers, John and Edward. John, the elder brother, was trained as an instrument maker by his uncle and became well known as an instrument maker who specialized in dividing the arcs of instruments for other craftsman which at that time he did by hand. In 1773 at age 20, Edward joined John as apprentice. Between 1775 and 1778, John constructed his own dividing engine, similar to the one of Jessie Ramsden's. The evenness of the spacing and markings on the ivory arc suggest that this instrument was one of the first made by this machine.

 

The Troughton business had a shop at 136 Fleet St., London. The business flourished and Edward became a partner with his brother who died shortly thereafter in 1788. This event was followed by Ramsden's death in 1800 leaving Edward Troughton to quickly become England's leading maker of instruments. For example, he designed the "pillar" sextant in 1788, the dip sector, a marine barometer, and reflecting circle in 1796 all of which is after the date of this octant. One of his most important contributions built on his brother John's and Ramsden's methods of dividing a circle, and in 1809 he was awarded the Copley Medal of the Royal Society for his invention which achieved greater accuracy. He was elected a member of the society in 1810.

 

This outstanding example of Edward and John's work is the most beautifully made instrument that we have ever had the pleasure to offer. It has an ebony frame, flat brass index arm, ivory graduated arc and vernier, and exquisitely made bronze fittings.

Troughton, London mark   Unusual Oak case, rounded corner

The metal fittings are precisely machined to a level of smoothness and finish that makes this instrument a true work of art and sets it apart from all other octants of this period. It is truly magnificent.

It is housed in a fan shaped Oak wood case with a green felt liner, and polished brass trim. The top of the case is curved, and the panels are fitted using the tongue and grove method, again a rarely seen and unusual feature. The initials "MI" are painted in white on its top.

The arc measures from - 5 to plus 95 degrees. It has a flat brass index arm measuring a long 13 3/4 inches, with a clamping mechanism rather than a tangent screw. The horizon mirror is mounted on an adjustable turntable. Its base can be rotated by loosening a screw which locks the mirror's position. Note the early form ivory vernier scale, reading from right to left from 20 to 0 arc minutes, a two hole peep sight with "shade glass", and moveable three sun shades which serve both mirrors on the frame. The index mirror is of very large size, and is in excellent condition.

All of these features date the instrument before the turn of the 18th century, likely Ca 1775. See Peter Ifland's comprehensive sextant work, "Taking the Stars". particularly figure 64, page 57.

 

Some time after 1780, the addition of a tangent screw, not on this instrument, allowed for fine adjustment and represented one of the two major changes in the basic operation of the octants and sextants for the next 150 years! The second was the fitting of telescopes. As was the practice with octant's of this larger size, only peep sights were fitted. Later a handle was added. The history of the brother's working together, and all of these tell tales indicate it is one of the earliest of that type.

Finely made fittings, large index mirror

The machinery

CONDITION: The instrument is in exceptional condition in all respects. The ivory graduated arc, and all its hardware are in like new condition and of the highest quality. It was lacquered some time ago, and has a wonderful patina of age under. All three bronze legs are present. It has the ivory pad on back, but is missing is the small ivory scribe. Both the index and horizon mirror are in exceptional condition and show as near new. The Oak case, has a lengthy age crack down its length, but is rigid, and is otherwise in excellent condition. All in all, a ver rare, desirable, and very special example from one of England's most famous instrument makers. DIMENSIONS: Arc reads - 5 to +95 degrees Length of frame 13 3/4" long Width of frame at arc 11 " wide Index mirror 50 x 34 mm Horizon mirror - 20 x 24 mm Three shade glasses Two Peep sights Weight 2 Lbs 12 oz CREDENTIALS: We are one of the few people on the web selling navigation instruments that know anything about them. For purposes of judging whether my opinion counts, I was the editor of the chapter on sextants of the 1977 Edition of "Bowditch", The American Practical Navigator, NAVPUB 9; a member of the U.S. Naval Academy Navigation Symposium Board, 1975-1978; the author of a book on marine sextants, Cornell Maritime Press,1975, and the founding president of Nautech Maritime Corporation which partnered with Tamaya of Japan in the introduction of the MS 733 Spica, the MS 833, Jupiter, MS 933 Venus sextants and the famous NC-2 navigation computer, in the U.S. market. I am also a retired Master Mariner, and held a U.S. Navy "D" Qualification as a Senior Skipper - Oceans OUR UNCONDITIONAL GUARANTEE: If not completely satisfied with your purchase it may be returned, if without damage, within three days of receipt in its original condition and packaging. Returns must be insured for their full value. All that is required is a prior email authorization by us for the return. Unfortunately, no refund can be made for the cost of shipping, packaging and handling unless we are at fault. INTERNATIONAL BUYERS WELCOME, but contact us first. We have customers in Australia, Austria, Belgium, Bermuda, Canada, Chile, China, Denmark, England, France, Germany, Holland, Hong Kong, Ireland, Israel, Italy, Japan, Kuwait, Martinique, Mexico, New Zealand, Norway, Nova Scotia, Saudi Arabia, Scotland, Singapore, Spain, Sweden, Switzerland, Thailand, USVI and the Eastern Caribbean. SHIPPING & PACKING: The cost of shipping, packing, handling, and insurance to your destination, is an additional charge. You may email us to get these costs. We price our shipping honestly, but we expect to be reimbursed for the nominal cost of packaging materials and handling. ACCEPTED FORMS OF PAYMENT are Bank wire transfer, cashier's check, money order, or personal check in which case the item will be held until cleared. No credit cards or PayPal accepted on big ticket items. Buy this very special article of maritime history Now! What a great find for that special person who can appreciate only the finest and most rare. Or donate it to a museum where it belongs. Copyright 2006 by Land And Sea Collection, All Rights Select a thumbnail from the left to zoom. Image #1 Image #2 Image hosting and Zoom Gallery by VillagePhotos.com