“Tom who?” asks our fictional Scotch and wry narrator (an earnest Alan MacKenzie as the son of a left-wing journalist with political ambitions). A sentiment echoed by many, if not most.

But given the incredible legacy of the electrifying protagonist at the heart of Robert Dawson Scott’s hour-long three-hander for Mull Theatre (played with wit and surety by Stephen Clyde), the three letters after his name should read, not who, but MBE.

Were it not for the small matter that, like Burns, he believed that “The rank is but the guinea’s stamp”.

With a CV that reads like a history of political radicalism in Glasgow and the social transformation of the Highlands and Islands following the Second World War, Scott hones in on what is considered to be Johnston’s greatest achievement: harnessing the natural resources of rainwater and hills (both of which are as abundant as midges) to generate electricity and set the “crofting counties ablaze with light”.

But doing so meant challenging the tax-receiving landowners – whom he had previously discredited in his “modest little volume” of “youthful jottings” Our Scots Noble Families (a precursor to Andy Wightman’s The Poor Had No Lawyers) – to part with their land or at the very least accept compensation.

A difficult task which he mastered through skillful negotiation – 96% of houses in the Highlands and Islands were eventually electrified – for as he wryly put it, the art of getting what you want is by dealing with those who want something in return. Namely, money.

Set against a backdrop of off-white flats upon which is delineated in black a circuit board of lines, triangles, circles and squares to represent the dams, tunnels, pipelines and power stations of what was considered to be the greatest civil engineering project in the UK, the plotting and dialogue is equally concise.

Electrifying, though, it is not.

Scott does a masterful job of weaving fact with fiction, but the exchanges are more cerebral than dramatic. In fact, the only time the embers crackle and spit is when the wisened hack belatedly grills Johnston on his poor safety record, for lining the pockets of greedy landowners and for failing to deliver on his promise of factories and industries.

The staging, too, lacks a spark of excitement. For many of the exchanges are delivered from static positions and the inter-scene gaps are at times so thumb-twiddlingly long that not even Martin Low’s sprightly score can camouflage the fact that the stretched cast of three are forced to make rapid costume changes backstage (an excellent Beth Marshall plays a carousel of female figures from crofter to castle dweller).

It’s far from a dry history lesson though – Johnston’s tongue-in-cheek threat of providing the 51st Highland Division with the addresses of parliamentarians opposed to hydro-electricity draws a wave of laughter from a ripple of titters – and many of the themes are as relevant now as then such as decentralisation, “a workforce of itinerants” and the political choice to reform the poor over the banking system.

Oh, what Scottish Labour would give to bask in the electrifying light of Mr Johnston today. Rather than huddle round a candle with a short wick.

Peter Callaghan