In the event the Sam Davis Memorial Association should at any time fail, neglect or refuse to improve the houses and grounds, and to keep them in a high state of beauty and improvement, then the houses and land and such other improvements as may be upon the grounds shall revert to the state of Tennessee without compensation to the trustees, Sam Davis Memorial Association or other corporation or person. The state shall not be required to pay any money whatever for such improvements as the trustees, Sam Davis Memorial Association or other person or persons may have made upon the houses or lands.