In comparison with the great variety of types and sizes of lathe that Britannia offered, their milling machines appeared to have been few both in the type and number of variations offered.
Typical of their vertical milling machines listed in the last years of the 19th century was the No. 14, a simply designed, modestly-sized affair with a 24" x 8.5" table power driven along the 18 inches of its longitudinal axis - but requiring hand feed on the 7.5-inches of cross feed, as well as on the generous 14 inches of vertical travel. None of the feed screws were fitted with micrometer dials.
Because the belts driving the table feed were flat, and needed to go round rather small pulleys, a mechanism was devised that gave them the maximum amount of "wraparound" - and hence grip. The arrangement of the belts was, of necessity, rather a convoluted one and began with a small 3-step pulley mounted on a extension to the back of the horizontal drive spindle; this drove down to a matching pulley carried in a bracket at floor level to the rear of the main column. From there the drive was carried forwards to a system of three parallel pulleys - around which the final drive belt must have been wrapped - and hence to the small pulley and its attached worm gear at table level.
The miller's 1.625-inch diameter vertical spindle echoed Britannia lathe practice, with an adjustable thrust plate supported on two columns; unfortunately, this type of arrangement precluded the fitting of cutters held in place with a draw bar - the spindle being blocked at the end and unable to be bored clear through. The spindle carried a 4-step cone pulley, driven by a 2.25" wide flat belt, with a largest diameter of 8.5 inches - and a smallest of 3.75 inches.
A lathe-like backgear assembly was fitted, greatly increasing the capacity for heavy, slow work, whilst the head of the machine was braced by a cast-in overarm. The large hole through the centre of the machine's body was to accommodate extra long workpieces - a useful facility that allowed the miller to tackle jobs that might otherwise have demanded the use of a much larger and more-expensive-to-operate machine..