EINSTEIN'S "MASCHINCHEN" 55 [1]Einstein 1907b (Vol. 2, Doc. 39). [2]"eine neue Methode zur Messung sehr kleiner Energiemengen" (see the following docu- ment). [3]For a detailed history of friction machines, see Hackmann 1978. [4]See, e.g., Heilbron 1979, pp. 416-417, for a discussion. [5]See, e.g., Schmidt 1918, pp. 33-40, for a description of various multiplying machines. [6]See Belli 1830-1838, vol. 3, pp. 394-397, 436-437, and Belli 1831. [7]The "siphon recorder" was a special galvanometer used for recording telegraph signals carried by submarine cables. The "replenisher" electrified the ink enabling it to flow through a very thin-writing siphon-tube. In the absolute electrometer the "replenisher" allowed the charge on a condenser to remain constant (see Thomson, W. 1872, pp. 330-339). [8]See Elster and Geitel 1885. [9]Einstein 1908a (Vol. 2, Doc. 48). [10]For a theory of these kinds of machines, see Maxwell 1881, pp. 375-378, and Graetz 1905, pp. 51-54. [11]It can be considered a multiplier only in the sense that when equilibrium is reached (after several cycles) the voltage on the collector is a multiple of the voltage on the inducer. [12]See Doc. 54. [13]"Interesselosigkeit der Fabrikanten" (see Doc. 69). Einstein's paper did generate some outside interest-in a letter to Einstein Joseph Kowalski, Professor of Experimental Physics at the University of Fribourg, expressed his interest in having a machine manufactured (see Doc. 94). [14]See Docs. 74 and 113. [15]See Doc. 122. [16]"meine selbstzusammengepfuschte Herrlichkeit" (see Doc. 125). [17]See Doc. 124. [18]See Doc. 143. [19]See Doc. 150. [20]See Doc. 187. [21]See Doc. 198. [22]Habicht and Habicht 1910. [23]One of the prototypes had only four stages. [24]See Einstein 1908a (Vol. 2, Doc. 48). [25]"Er hat nun den Widerstand gegen diese Sache gebrochen ich glaube, dass das Maschin- chen bald das empfindliche Quadranten & Fadenelektrometer verdrängt haben wird" (see Doc. 330). [26]See, e.g., Schmidt 1918, p. 35, where it is claimed that self-induction makes it impossi- ble for the instrument to function properly. [27]See also Doc. 402, in which Habicht lists atmospheric electric phenomena caused by a thunderstorm (or even by an imminent storm) as another cause of disturbances. [28]See Doc. 296. The Habicht brothers tried to avoid these effects by gilding all the metallic parts of the first two stages of the multiplier (see Paul Habicht's Gebrauchsanweisung für den Potential-Multiplikator nach A. Einstein, SzWT). The gilding is also mentioned in Doc. 354. [29]See Habicht's descriptions of these accessories in the supplements to the Gebrauchsan- weisung (see the preceding note). [30]It was purchased around 1920 by Friedrich Paschen, Director of the Institute. A metal label on the instrument reads: "Paul Habicht / Schaffhausen, Schweiz / Potential- Multiplikator / Type 6 N°0018/Motor PS 1/150 Volt 2-4" (see Gedächtnisausstellung 1979, pp. 49-50). A picture of it is presented as illustration no. 5 in this volume. [31]See Cotti 1989, pp. 13-14. [32]A metal label on the instrument identifies it as number 35 otherwise the label is identical to the one on the copy kept in Tübingen (see note 30).