Related Clues:
- Strong and stout
- Not hollow, the same throughout
- Strongly and solidly built
- Thus the top has not got a hole in it
- Thus it's not a hollow top
- Are, by the sound of it, strong in the study
- Thus, no hollow cover
- Thus on the cover there's no hollow
- Not a liquid or a gas
- Not liquid or gaseous
- Type of geometry
- It's not liquid
- We shall shortly join firm
- Financially sound southern lido, perhaps
- One inside betrayed firm