Titchener's Photo Album - continued...

Carl Diederichs, Göttingen, Germany

Diederichs was an established maker of instruments who supplied psychological instruments to the laboratory of Georg Elias Mueller at the University of Goettingen. Diederichs and his partner Bertels had been employees of the firm Meyerstein and bought the company in 1875. In time the firm became known as Carl Diederichs. Diederichs may have had a printed catalogue in 1895 but reported in a letter to Titchener that he had none left to send out. Instead he sent a hand written copy of the price list along with photographs and hand written extended descriptions of some of his instruments. In 1898 Diederichs was bought out by two employees, August Spindler and Adolf Hoyer, later changing the company name to Spindler and Hoyer (for two catalogs of that firm, see their 1908 price list Apparate für psychologische Untersuchungen and their 1921 catalogue Apparate für psychologische Untersuchungen)

G. E. Müller and F. Schumann's Memory Drum. Diederich's photograph is of the first commercially available memory drum

Photographs of the following instruments were included in Titchener's album:

• Chronograph according to Schumann (extended description, see also price list, Nr. 5);
• Schumann's tuning fork time marker of the chronograph (description, price list, Nr. 8);
• Simple reaction key for the electric stimulation of fingers (left) and fivefold key for dialing attempts (right) (description, price list, Nr. 14 (left) and Nr. 15 (right));
• Keys for Schumann's time sense apparatus (left) and rotation device for Schumann's time sense apparatus (right) (description, price list, Nr. 3 (left) and Nr. 2 (right));
• Helmholtz's light interruptor (description, price list, Nr. 10);
• Müller's and Schumann's rotary apparatus for experiments in memory (see also above) (description, price list, Nr. 1);
• Schumann's new time sense apparatus (description, price list, Nr. 4);
• Helmholtz's electric rotary apparatus (description, price list, Nr. 9).

Michigan Apparatus Company. Ann Arbor, Michigan, USA

Very little is known about this company which was established to make instruments for Walter Bowers Pillsbury's psychological laboratory and Warren Lombard's physiology laboratory at the University of Michigan. The company existed before 1899 but was out of business by 1905. One supplement to their catalogue is known to exist but no full catalogue.

Kymograph Drum mechanism

On one page in Titchener's album, the following instruments by that company are shown: a worm gear rotation converter (top right), an electro-magnetic recording stylus for kymographs (top left), a kymograph drum mechanism (bottom left, see also above), and two views of an electro-magnetic recording stylus for kymograph (bottom right).