| Rating | Solver | Clue |
|---|---|---|
| SKY | Upper atmosphere | |
| OZONE | Gas in upper atmosphere | |
| CLOUD | A collection of visible vapor, or watery particles, suspended in the upper atmosphere. | |
| ETHEREAL | Pertaining to the hypothetical upper, purer air, or to the higher regions beyond the earth or beyond the atmosphere; celestial; as, ethereal space; ethereal regions. | |
| SYMPIESOMETER | A sensitive kind of barometer, in which the pressure of the atmosphere, acting upon a liquid, as oil, in the lower portion of the instrument, compresses an elastic gas in the upper part. | |