My dear Tom.
The idea is a nice one. nevertheless you cannot I think say broadly that we are unable by the mere act of the will to change our state of rest. For the change of form you admit is in point of fact a change of rest. and I believe this changing of form is possible even when you have no fulcrum. This I see is your meaning. You require therefore simply to change the sentence ‘no mere effort of the will can change our state of rest’ – The parts of the body may move with reference to each other, but not the whole body with reference to external objects. I would restrict the phrase. ‘where we see an inanimate body in motion’ to ‘where we see an animal walking.’
I would leave out the last short paragraph. The subject is so deep that the last allusion only creates a haze and will leave no clear impression. – end the matter with the word ‘Motion’ –
I could shew you almost the same series of thoughts written down in my Journal, and suggested by watching the movement of the horses in a post wagon2 during a fine starlight night between Brunswick3 and Göttingen.
Send me Pouillet Müller.4 The news of Queenwood is gladdening,5 glorious in fact. Go on and prosper.
your affectionate | John
I will go down to your Xmas concert if I can
RI MS JT/1/T/927
RI MS JT/1/HTYP/276
[25 October 1853]: the contents of this letter correspond to Tyndall’s journal entry for 25 October, in which he recorded the receipt of a letter from Hirst noting the large number of boys at Queenwood (Journal, JT/2/13b/630). Furthermore, LT notes: ‘Art[icle]. on Progressive Motion in Q[ueen]wood Observer written Oct 23, inserted Nov 9 – see H[irst’s]. J[ourna]l VII. This letter w[oul]d probly be about | 25th [October]’. In his journal entry of 23 October, Hirst recorded the writing of this article; it also contains the only known copy of the article (Hirst, ‘Journals’, 23 October 1853).
the same series of thoughts … horses in a post wagon: Tyndall was referring to his journal entry of 27 August, which states, ‘A clear cold night, something spectral in the motion of the horses. Something very beautiful in the loyalty with which they breasted the road at the command of man. Watched the motion of the limbs, the hind-leg first drawn up by the contraction of the muscles, the hoof placed on the ground and the muscles then stretched to throw the animal forward. Thought of the nerves, their influence is wonderful, if we snap one of those strings which of itself will not bear a pound weight we deprive this great machine of the power of action. How is it that they are made the channels of the will? The fracture of a single thread in a factory is sufficient to stop the works, the finger of an engineer can set a locomotive in motion it merely loosens agencies which far transcend the power applied to set them free. Does something similar occur in the case of the nerves?’ (Journal, JT/2/13b/620).
Brunswick: the English name for the city of Braunschweig, located in northern Germany.
Pouillet Müller: M. Pouillet and J. Müller, Pouillet’s Lehrbuch der Physik und Meteorologie, für deutsch verhältnisse frei bearbeitet von Dr. Joh. Müller, 2 vols (Braunschweig: Vieweg, 1842).
The news of Queenwood is gladdening: see n. 1.
Please cite as “Tyndall0812,” in Ɛpsilon: The John Tyndall Collection accessed on