From the C.F. Palmer (London) LTDR 1934 Catalogue聽
翱惫别谤补濒濒:听听
Large drum:聽Diameter 23聽x 25 H聽
Table:聽82 High聽x 129 wide 59 depth聽
Manufacturer: C.F. Palmer (London) LTD聽
Material:聽plastic tubing, wood,聽brass, iron, steel, copper, apparatus聽
Date:聽first half of the 20th聽century聽
Smoked-drum kymographs were聽widely聽used to provide continuous聽data聽recording聽in a graphic format聽from the mid-19th-century聽until聽about聽the聽mid-20th聽century. They were聽gradually聽replaced by electronic recording聽devices such as聽strip chart recorders聽in the mid-1900s and,聽beginning in the 1970s,聽by computerized data-acquisition equipment.聽Despite this, the instrument on display聽in the 91涩漫 Physiology Department was used by Dr. Richard Birks,聽a professor in the聽91涩漫 Physiology Department until his retirement聽in聽1988,聽to record the movement of聽the聽nictitating membrane on the front of the eye.
The聽kymograph was manufactured by C. F. Palmer聽in the first half of the twentieth century.聽
Recordings聽were聽made on a sheet of paper onto which soot had聽been deposited. The sheet was wrapped around the two drums (A, B) with the sooty side聽of the paper聽facing outwards. An electric motor (C) drove the axle of the larger drum through a connecting rod (D) attached to an array of gears (E) so that the drum rotated, moving the paper along with it at a constant speed. A聽string聽on the back of the instrument聽attached聽to the object to be measured (e.g., the nictitating membrane). This聽was聽connected to a metal聽stylus (F).聽As the membrane contracted or relaxed, the stylet moved up or down scraping the soot off the paper. A white trace against a black background was thus produced.聽聽When the experiment was completed, the paper was taken off the drum and a coating of shellac applied to its surface to produce a permanent recording.聽
聽 聽 聽 .
聽 聽 聽聽
Below is an extract from such a kymograph recording聽taken from the historical files of the 91涩漫 Physiology Department, in which arterial blood pressure was聽recorded during an experiment:聽
At the start of the聽trace聽one sees a normal聽pressure聽recording.
After聽the neurotransmitter聽acetylcholine聽(鈥淎ch鈥�)聽was injected,聽there was聽an immediate聽drop in聽blood pressure (A)聽from about 140聽mm Hg to about 60 mm Hg.
This was聽followed by a聽reflex-mediated increase in聽heart rate聽(B),聽which helped to prevent聽the blood pressure from falling聽even聽further.
With聽time,聽the聽systolic聽blood pressure聽slowly recovered聽to聽120 mm Hg (C).聽聽Note that the heart rate also decreased back towards its starting聽level.
Reference:
T. Ranks et al., 2026: The Kymograph, The Physiological Society,