The challenge was breathtaking in the extreme, two men in a flying machine aiming to earn a special place in aviation history by being first to cross the Atlantic non-stop and pick up a prize worth £1 million today for doing so. 

The incredible feat was accomplished 100 years ago this month when a converted First World War bomber piloted by John Alcock and Glasgow-born Arthur Whitten Brown touched down in the soggy bog of Derrygimla Moor with a rather undignified thump that saw the aircraft dive nose first into the County Galway mud. 

They had flown around 2,000 miles from Newfoundland – often in poor visibility and at one point in the face of a vicious snowstorm that resulted in a remarkable feat of bravery on Brown’s part when, mid-flight, he fearlessly climbed over Alcock in the pilot’s seat and on to the wings to unclog the air filters. 

Their death-defying achievement – complete with a cargo of letters from America – combined pioneering determination and an engineering miracle in the form of their modified, twin-engined Vickers Vimy biplane. 

But it would have been all the more challenging without the invention of a Glasgow-born boatbuilder, whose deceptively simple innovation would carve its own little bit of history in aviation, on mountainsides, on the sports field and, perhaps less significantly, in homes across the land. 

Above Guthrie McGruer’s dining table, suspended from an oak beam, is a length of polished and varnished wood, teardrop in shape over 2 metres long and about 20 cm in circumference. Despite its size, it is so light it can be balanced on a child’s index finger. 

Visitors to his Monmouth home in Wales are often intrigued by the wooden ornament. According to Mr McGruer, they are even more fascinated to learn how it has a very special place in world aviation history. For without it, that first non-stop crossing of the Atlantic, might not have taken off. 

The varnished wood, he explains, is a replica of one of the Vickers Vimy’s wing struts. Its incredible lightness – a crucial factor in aiding the plane as it battled across those 2,000 miles – was made possible due to a remarkable invention patented by his Glasgow-born grandfather, Ewing McGruer, in 1915. 

The eldest son of the well-known McGruer boatbuilding family, he was known for his innovative methods in yacht construction and design, particularly the use of spars in masts and booms for racing yachts.  

Mr McGruer said: “By carefully examining the end grain of a thin plank of sawn Sitka spruce, he found that where the angle of the grain was 45˚ to each side of the plank, it could be placed on a metal spindle, heated on one side and with water applied to the other the wooden fibres would contract and expand respectively. The thin wood could then be bent or rolled around the spindle.  Waterproof glue would be applied to each edge and planed off.”

The “rolled hollow spar” could be adapted to different degrees of strength using wooden tubes and laminated coils. And its discovery would help revolutionise all manner of items.

A McGruer rolled hollow spar boom measuring 85ft long was fitted to King George V’s royal yacht Britannia, while the War Office commissioned London-based McGruer Hollow Spar Company to churn out scores of wing struts for fighter and bomber biplanes deployed in France. 

Hollow spars are found in wireless masts, organ pipes, walking sticks, billiard cues and even the rugby posts at Twickenham. In 1924, George Mallory’s Everest expedition carried with them McGruer hollow spar ice pick handles. 

But it was the incredible Atlantic crossing that would see McGruer’s invention make aviation history. 

Alcock and Brown set off on June 14 1919 from a makeshift runway, their plane’s former bomb racks replaced with petrol tanks. The wind-driven electrical generator failed leaving them without radio contact, intercom and heating, while a burst exhaust pipe caused a deafening racket.

But they landed after 16 hours in the air and were instant heroes, knighted by the king.

Mr McGruer adds: “I and my family take immense pride in the achievement of my grandfather.”