Description and Notes:
This set is dated to c1850 due to the fact that the maker of the sector rule, T. Bradburn & Sons, were in business from 1834 to 1852, as indicated in Directory of British Scientific Instrument Makers 1550-1850. In addition, although there are no maker's name or mark on any of the other instruments in this set, the style of the ruling pen, that the handle of which is made of brass and can be detached (screw out) from the middle to reveal a pricker, and that the long joint construction of the compasses are consistent with those from the early nineteenth century. It is also worth to note that the sector is made of boxwood which seems more difficult to find nowadays than those of ivory.
There are different opinions among the collectors about whether to clean the antique instruments. Mine is that if the instruments are acquired in a rusty state as this set, then, to prevent their condition from worsen, it is necessary to give the surfaces a light polish by using worn hand pad with light lubricant fluid such as WD-40 to remove the rust on the steel and the brass verdigris, but should never be overdone (i.e. to completely remove the patina). After the cleaning, the steel parts are heated by using hair blower to accept a thin coat of Vaseline to protect them from rusting again.
Upon acquiring there was no key for the lock and the lock plate was detached from the cover of the solid mahogany box, but the original screws are still there, so it is easy to restore. I have also found a matching replacement key for the lock so this is now a complete set (the divider at the top slot shold be an extra to the original set).