4.22 J/cal - whale oil
4.24 J/cal - mercury
4.15 J/cal - water (40expts)
4.16 J/cal - mercury
800 lb hammer moving 15ft/s smashed 6lb Pb block against 1 ton stone anvil, TPb increased 5oC
| Date | Who | Method | Result |
|---|---|---|---|
| 1798 | Rumford | |
5-6 J/cal |
| 1799 | Davy | |
|
| 1839-1843 | Joule | |
5.3 +/- .5 J/cal |
| 1842 | Mayer | Coined "Mechanical Equivalent of heat" - estimates from specific heats of gases | 3.5 J/cal |
| 1843 | Joule | water driven through fine tubes heated by fluid friction.
|
4.22 J/cal |
| 1844 | Joule | air compressed by piston pump.
|
4.42 J/cal |
| 1845 | Joule | ditto, greater compression | 4.27 J/cal |
| 1845 | Joule | Compressed air from bottle in water bath, expanded, pushing away atmosphere
and thus cooled (effect now used to manufacture liquid gases and dry ice). |
4.4 +/- 0.4 J/cal |
| 1847 | Joule | |
4.21 J/cal
4.22 J/cal - whale oil 4.24 J/cal - mercury 4.15 J/cal - water (40expts) 4.16 J/cal - mercury |
| 1850 | Joule | |
4.21 J/cal |
| 1857 | Hirn | Boring metal with dull bit | 4.16 J/cal |
| 1861 | Hirn | water-cooled metal brake | 4.23 J/cal |
| 1861 | Hirn | 800 lb hammer moving 15ft/s smashed 6lb Pb block against 1 ton stone anvil, TPb increased 5oC |
4.17 J/cal |
| etc. etc. etc. | |||
| 1878 | Joule | Water churned by paddle, improved apparatus, weighted average of 34 experiments, masses reduced to weighings in vacuum and corrected to gas-thermometer. | 4.172 J/cal |
| 2005-2006 | PHY 105 | tip-tube | 4.2 +/- .8 J/cal |