What marks out the clock at St Martin's is the way the time is displayed. That has probably always been true.
Public clocks served a public purpose. They were placed in the most prominent and convenient place, almost always a church until the proliferation of municipal public buildings from the mid-19th century onward. A position in the tower meant that they could strike the hours and quarters, indeed the earliest such clocks did only that. But in the crowded space of a city a tower dial would be visible from few locations, and that was true of St Martin's. Mounting it directly onto the wall of the church itself was an option frequently adopted despite the inconvenience to worshippers of the noisy movement. That was satisfactory if the street was reasonably broad or the church was on a corner location. Rather better in most street locations was to project it into the street. St Martin's is an early example in 1668. St-Dunstan-in-the-West, in London's Fleet Street, adopted a similar arrangement in 1671 though in that case with the considerable embellishment of a mechanism housed in a wall recess above in which two figures struck the hours and quarters.
Having been positioned for their utilitarian purpose some places stuck with that, and it must be remembered that any refinement depended on the willingness and ability of local residents to pay for it. Coney Street was clearly seen as deserving more, and the earliest description of the clock, by Thomas Gent in 1730, refers to its 'curious' dial with an Archimedes pointing to the sun. Quite what that decoration was, and whether it survived the repairs and redecorations of the eighteenth century, it is difficult to be sure but it is probably not too fanciful to suppose that it in some way inspired John Agar's 1788-9 unique provision of a figure above the dial who himself followed the sun. The 1788-9 bracket and ornament we know in some detail because several illustrations, including a photograph, survive although sadly there is no clue to the painting scheme. It seems appropriately in period to decorate and embellish a public clock in this way, but for all the exuberance and expense of its strike the clock at St-Dunstan-in-the-West, for example, seems always to have offered a severe and practical face to the world.
Just how much design freedom Thomas Cooke was given for the 1856 replacement we do not know, only that he was to retain the earlier figure, but his bracket and ornamentation, though in no sense a copy of Agar's, retains the same spirit and exuberance. The only subsequent change of note was the replacement of most of the wooden ornaments with metal in 1883. Interestingly the final estimate states that this was to be with brass, but what we have is of iron, a cheaper material but requiring more effort to form, a reminder of York's engineering skills of the period. The wood that remained suffered badly in the fire of 1942. The admiral largely survived, though with a lost arm and badly charred back that was replaced and probably some loss of detail around his head. The badly charred face of Father Time at the end of the bracket was substituted by a new one carved in the Minster workshops, but unlike the Admiral failed to withstand exposure to the elements and had to be replaced again in 2012 with a resin cast.
Public street lighting did not arrive in York until the 1820s. The 18th century clock had gilded numerals and hands against a dark dial which was the most visible in poor light. But for the 1850s replacement the city's Board of Health, then responsible for street lighting, agreed to fund the lighting of the dial by gas. Thomas Cooke's 1856 clock had dials illuminated by 'self actuating' gas lights inside the drum. How that worked is unclear but presumably there was some sort of mechanism linked to the clock itself to turn the lights on and off. We do know that it was unsatisfactory because the the Board of Health became very frustrated and complained angrily to the church about the failure to fix the problems, and whether or not the automatic mechanism was a success the gas flares themselves, which at that date would not have had mantles, seem to have caused the dials to blacken and crack. The absence of any mention of lighting in the 1880s refurbishment or subsequently suggests that any attempt to light the dial was abandoned.
Geoffrey Newey fitted four ordinary household bulbs inside the drum of the 1966 clock, operated by a very sophisticated electromechanical time switch which kept pace with the seasons. The one drawback was that to change the bulbs, with a 1000 hour service life, required Mr Newey to climb a ladder and get inside the drum through a hatch on the top, something that he did regularly until increasing age and more rigorous health and safety regulations rendered that impossible.
For the 2012 refurbishment a more durable solution was sought. LED strip lighting around the internal circumference of the drum was the initial proposal, but after a good deal of experimentation the Cumbria Clock Company came up with the solution of fitting internal diffusers and illuminating the dial internally with LED floodlights triggered by a photo electric cell. With an expected maintenance free life of at least 20 years the clock has for the first time a truly practical and cost effective night time display.