instrument to the Annalen. Reis answered him,'Ich danke Ihnen recht Sehr, Herr Professor; es ist zu spät. Jetzt will Ich nicht ihn schickeny. Mein Apparat wird ohne Beschreibung in den Annalen bekannt werden.' ('Thank you very much, Professor, but it is too late. I shall not send it now. My apparatus will become known without any writing in the Annalen.')
Latterly Reis had confined his teaching and study to matters of science; but his bad health was a serious impediment. For several years it was only by the exercise of a strong will that he was able to carry on his duties. His voice began to fail as the disease gained upon his lungs, and in the summer of 1873 he was obliged to forsake tuition during several weeks. The autumn vacation strengthened his hopes of recovery, and he resumed his teaching with his wonted energy. But this was the last flicker of the expiring flame. It was announced that he would show his new gravity-machine at a meeting of the Deutscher Naturforscher of Wiesbaden in September, but he was too ill to appear. In December he lay down, and, after a long and painful illness, breathed his last at five o'clock in the afternoon of January 14, 1874.
In his Curriculum Vitæ he wrote these words: 'As I look back upon my life I call indeed say with the Holy Scriptures that it has been "labour and sorrow." But I have also to thank the Lord that He has given me His blessing in my calling and in my family, and has bestowed more good upon me than I have known how to ask of Him. The Lord has helped hitherto; He will help yet further.'
Reis was buried in the cemetery of Friedrichsdorff, and in 1878, after the introduction of the speaking telephone, the members of the Physical Society of Frankfort erected over his grave an obelisk of red sandstone bearing a medallion portrait.