| Subject |
|---|
| Ram [1] |
| Recipe [1] |
| Recoil [1] |
| Recreations [1] |
| Redoubts [1] |
| Rene Descartes [4] |
| Repulsion [1] |
| Respiration [1] |
| Retrograde motion [1] |
| Rome [2] |
| Rotation [1] |
| Rudder [1] |
| Sailing [1] |
| Sappho [1] |
| Saturn [2] |
| Seasons [1] |
| Senses [1] |
| Shapes [1] |
| Shield [1] |
| Ship [1] |