I gave up my lodgings on quitting Munich, and managed so as to settle all concerns of business. I flatter myself I am settled down here for life, far removed from wars and all arduous duties, as a recompense for past services, with plenty to live upon and at liberty to pursue my own natural propensities, such as have occupied me through life—a life, as I try to fancy, that may come under the denomination of a benefit to mankind.
Next spring we are going to travel into Italy and the south of France, to be gone two years, so you must patiently stay where you are for the present.
You will wish to know what sort of a place we live in. The house is rather an old-fashioned concern, but in a plot of over two acres of land, in the very centre and finest part of Paris, near the Champs Elysées and the Tuileries and principal boulevards. I have already made great alterations in our place, and shall do a vast deal more. When these are done I think Madame de Rumford will find it in a very different condition from that in which it was, that being very pitiful with all her riches.
Our style of living is really magnificent. Madame is exceedingly fond of company, and makes a splendid figure in it herself. But she seldom goes out, keeping open doors; that is to say, to all the great and worthy, such as the philosophers, members of the Institute, ladies of celebrity, &c.
On Mondays we have eight or ten of the most noted of our associates to dinner. Thursdays are devoted to evening company, of ladies and gentlemen, without regard to numbers. Tea and fruits are given, the guests continuing till twelve or after. Often superb concerts are given, with the finest vocal and instrumental performers.
At this time Sir C. Blagden wrote to Sir Joseph Banks:
I have received a letter, dated November 22, from a lady in Paris, which contains no kind of news except the following article about Count Rumford and his lady: ‘Madame Lavoisier s’appelle à présent Madame de Rumford. J’ai vu Madame de Rumford [the writer of the letter has been returned to Paris only two days]. Ils ne donnent ni l’un ni l’autre aucun détail sur leur mariage ni sur l’époque; un jour ils l’ont dit à leurs amis, et il n’y a pas eu plus de formalité que cela. Ils sont sur un pied fort amical, mais ils étaient ainsi depuis longtemps. La maison de Mdme. de Rumford est charmante. Elle l’embellit tous les jours et avec beaucoup de goût.’
On January 15, 1806, Rumford wrote to his daughter:
The newspapers will acquaint you with the other particulars of this peace, which will occasion a great change in the political state of Germany, as, in fact, of all Europe. I hope that I shall not, and I do not think that I shall, lose by any of these changes. At all events the Elector, or rather the new King, has just written me a very kind letter, giving me hopes, rather than suggesting fears of anything of a disagreeable nature. But dependencies like mine can never be otherwise than uncertain, as I feel it, notwithstanding my marriage. I may make a change, after all, but never certainly to the disadvantage of anyone. Between you and myself, as a family secret, I am not at all sure that two certain persons were not wholly mistaken, in their marriage, as to each other’s characters. Time will show. But two months barely expired, I forebode difficulties. Already I am obliged to send my good Germans home—a great discomfort to me and wrong to them.
On March 8, 1806, Sir C. Blagden, who had quarrelled with his friend because he thought that Count Rumford had not defended him from the imputation of acting as a spy in Paris in 1803, wrote to Rumford’s daughter regarding the marriage:
They are now living together in Paris, and, as far as I can learn, very happily. I know nothing of it from your father himself, which is not surprising, as I some time since intimated to him my wish that our correspondence should cease. We are not, to the best of my knowledge, on terms of enmity, but it is not likely that any kind of confidence or friendship should subsist between us again.
In 1806 and 1807 Count Rumford sought for relief by the pursuit of science. He published in the Memoirs of the mathematical class of the Institute a continuation and extension of his investigations on light and heat. These were in the sixth, seventh, and eighth volumes, and made nine papers. 1. ‘A Description of a New Thermoscope or Differential Thermometer.’ 2. ‘Researches on Heat, Showing the Effect of Difference of Surface on Radiation.’ 3. ‘Further Experiments on the Effect of Blackening the Surface.’ 4. ‘Researches Continued on the Different Properties of Bodies with Respect to Radiation and to Conducting Powers.’ 5. ‘Further Researches on the Passage of Heat through Solids.’ 6. ‘Experiments on the Heat of the Solar Rays.’ 7. ‘Remarks on the Temperature of Water at the Maximum Density.’ He made it 41° F. or 5° C. This paper was published in the ‘Philosophical Transactions.’ 8. On the ‘Dispersion of the Light of Lamps by Screens of Ground Glass, Silk, and so forth, with a Description of a New Lamp.’ He had an illuminator constructed and presented to the Institute. This paper was published in England as his sixteenth essay on the ‘Management of Light in Illuminations.’ 9. On the ‘Cooling of Liquids in Vases of Porcelain, Gilt or not Gilt.’
In October 1806 he gave this sad account to his daughter:
My dear Child,—This being the first year’s anniversary of my marriage, from what I wrote two months after it, you will be curious to know how things stand at present. I am sorry to say that experience only serves to confirm me in the belief that in character and natural propensities Madame de Rumford and myself are totally unlike, and never ought to have thought of marrying. We are, besides, both too independent, both in our sentiments and habits of life, to live peaceably together—she having been mistress all her days of her actions, and I, with no less liberty, leading for the most part the life of a bachelor. Very likely she is as much disaffected towards me as I am towards her. Little it matters with me, but I call her a female dragon—simply by that gentle name! We have got to the pitch of my insisting on one thing and she on another.
It is possible that, had the war ceased raging, and had we gone into Italy, where she is dying to go, and with me too, she having heard me speak much of the delights of that country, she having been very happy, too, in travelling with me in Switzerland, it might have suspended difficulties, but never have effected a cure. That is out of the question. Indeed, I have not the least idea of continuing here, and, if possible, still less the wish, and am only planning in my mind what steps I shall take next—to be hoped more to my advantage. Communication with England is prohibited, and it makes me sad.