The Scientist King is not a sentimental being. He finds the softer emotions useless. That said, he has a large soft spot for 4 of his earliest creations. Though crude and rudimentary compared to his later works, these creations still fulfill their purpose. He personally maintains them.
One is the Overland Locator. This rickety giant has a special device that can locate resources from above. It's been especially useful in finding rare items the underground workforce may have missed.