The Duke of Edinburgh's inquisitive nature proved tiring for a trainee jockey today when he asked for a horse simulator to be speeded up during a demonstration.
The teenage rider was left hanging on to the reins of the mechanical animal after Philip's request during a visit with the Queen to one of the world's top stud centres in Ireland.
Horses are the Queen's passion and she is a dedicated breeder and racer who sends her own mares to the National Irish Stud toured by the royal couple today.
Her familiarity with horses was revealed at one point when a nervous thoroughbred reared up on its hind legs when paraded in front of its stables.
Some of the entourage standing near her instinctively moved back but she did not flinch and the stallion was soon brought under control.
In the immaculate grounds she toured small marquees showcasing all aspects of the horseracing world, from farriers to veteran jockeys.
The stand showcasing the trainee riders particularly captured the interest of the royal couple.
Sophie Ralston, 18, was in the saddle of the simulator, nicknamed Henry by the students, riding at a steady canter until the Duke asked: "Can you vary the pace?"
The easy demonstration became a taxing ride as Brian Walsh, chief riding instructor at Ireland's Racing Academy and Centre of Education, replied: "Yes, I can get Sophie to put up the speed and give it a gallop."
The teenager, from Craughwell in County Galway, was left racing away as the royals watched.
After a few moments the Queen turned to the Epsom Derby-winning jockey Johnny Murtagh, who was part of her group, asking him if he used something similar when training.
The Irishman replied, joking: "It wasn't as high tech as that - it was a bale of straw."
The Queen inherited her love of racing and horses from her mother - an avid National Hunt racing fan - and visits the races regularly, both officially and as a private spectator.
One of the Queen's colts, Carlton House, is running in the Derby next month and is likely to start as favourite.
Hosting her visit was fellow horse breeder Lady Chryss O'Reilly, chairman of the board of the Irish National Stud, and wife of industrial magnate Sir Tony O'Reilly.
Top stables from across the world are charged thousands for their mares to breed with the stallions at the Stud, with the most expensive horse - Invincible Spirit - costing more than £50,000.
Before leaving, the Queen unveiled a sculpture by Anthony Scott, whose work is collected by celebrities such as Dame Judi Dench and Daniel Day-Lewis.
He had created a work based around the original private owner of the stud, Colonel William Hall-Walker, who would select foals by their horoscope.
The artist created a large hollow bronze sphere with star constellations mapped on the outside and a stylised horse figure inside.
Mr Scott said: "This idea of the colonel using horoscopes was eccentric and ridiculed at the time but I drew on it for inspiration.
"The stars in the constellation are represented by small holes on the globe so when the sun shines, the light penetrates inside, creating a dappled effect.
"The Queen looked interested and was fascinated by the work. She liked the play on words on the famous horse's name Sea the Stars for the piece, which is called Sea of Stars."
A visit to see the retired champion Irish thoroughbred colt Sea the Stars - famed for his string of victories in classic races - was the next stop for the Queen when she made a private visit to the Gilltown stud owned by the Aga Khan.