A very fine and quite rare example of the Midland Railway Rotary Interlocking non-pegging block Instrument. In excellent condition except for a small chip of wood missing from the groove that holds the rear cover in place (see photo).  Needle pivots, bearings and coils are in perfect condition and operate as they should at around 3-volts.  Lock coil operates correctly at a similar voltage.   

These instruments seem to be much harder to get hold of than the pegging rotary block instruments with which they are paired.  Although it looks superficially like a standard Midland pegger,  the handle (an especially shortened version) does not hold in position and is not used for block signalling, but instead it allows the block indicator needles to be used for passing routing information and train descriptions.  The instrument is also fitted with a 'Line Clear Cancel' button for use with the rotary interlocking system.

Quite a heavy instrument, at almost 14Kg.