692 POPULAR SCIENCE MONTHLY. 



water, but his process was not applicable to the alcohol thermometers 

 then in use, for the vapor of alcohol has a tension at the boiling 

 point of water which would burst the reservoirs of the instruments. 

 And Renaldini's method could not be adopted till after Musschen- 

 broeck had introduced the use of mercury. In 1729, Delisle chose 

 as graduating points the temperature of ice-water and the almost 

 invariable temperature of the cellars of the Observatory at Paris. 



About 1714 a skillful instrument-maker of Dantsic, Daniel 

 Gabriel Fahrenheit, furnished chemists with alcohol thermometers 

 which he replaced in 1720 with mercury thermometers, the indica- 

 tions given by which all agreed with one another. According to the 

 chemist "Woulfe, he boasted that he could make a thermometer that 

 would agree with those he had already made, in any place, and with- 

 out seeing any of the instruments that had already gone out of his 

 hands; but he would not divulge the process by which he had been 

 able to obtain such an agreement. This process, in establishing 

 which he had been aided by the advice of the astronomer Roemer, 

 was nothing else than the method devised by Dalence; but Fahren- 

 heit took for his zero the temperature of a mixture of ice and 

 muriate of ammonia (chloride of ammonium) — which, he thought, 

 was the greatest cold that could be obtained — and for his higher de- 

 gree the temperature of the human body. 



Finally, in 1742, the Swede, Andrew Celsius, proposed to 

 restore the method of Renaldini, and divide into a hundred degrees 

 the interval which the mercury in the thermometer would traverse 

 between the temperature of melting ice and that of boiling water. 

 He marked the lower temperature 100, and the higher 0. Linnseus, 

 reversing this order, gave the mercury thermometer (centigrade) 

 the form under which it is now known. — Translated for the Popular 

 Science Monthly from the Revue des Deux Mondes. 



Carl Vogt, his son William relates, thought little of honorary titles 

 and decorations, and generally refused them when offered him ; while he 

 highly appreciated sincere and spontaneous tributes to the value of any- 

 thing he had done. Finally, his friends convinced him that a traveler 

 who could exhibit some badge of knighthood might receive better treat- 

 ment at the customhouses than one who had none, and he accepted the 

 last cross of the French Legion of Honor that Gambetta conferred. At 

 dinner one evening in Berlin, his hostess, after proudly exhibiting her 

 ordei-s, asked him about his. He had none, he said, except the cross that 

 Gambetta gave him. Perceiving that this was not well received, he be- 

 thought himself, and added : " Ob, I forgot. I wear, too, the blue and white 

 badge of the Society of Cooks of Munich, and am very proud of it, because 

 they gave it to me of their own accord after I had translated Brillat- 

 Savarin." 



