Recalling her discussions with the Royal Engineer, she remembered that it was some kind of device for determining how far any object was, even if its size wasn't known. All she really knew was that he had spotted it in a supply catalogue, he had insisted that a pair be lent to him. The palace depot commander had tried to stonewall him, saying it was an extremely precious piece of equipment, normally used only on boats, and that they didn't stock such items in the palace anyway. Her VIP hadn't relented, looming over the commander and waving Celestia's writ. In the end, two of the depot underlings had wound up having to gallop halfway out of the city, all the way down to the riverside naval depot, to get it for him.