MicroscopyPioneers
Pioneers in Optics: Étienne-Jules Marey and Ignazio Porro
Michael W. Davidson National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32306
davidson@magnet.fsu.edu
Étienne-Jules Marey (1830–1904)
Étienne-Jules Marey was born in Beaune, France, on March 5,
1830, to a wine merchant and a teacher. To satisfy his father’s wishes, he decided to study medicine, attending the Faculty of Medicine in Paris. Marey’s fascination with both animals and mechanics inspired him to concentrate on physiology, and it was during his investigations of this field that he became involved in optics. Due to a personal opposition to vivisection, Marey was
inspired to find new ways to study subjects. Because his primary interest lay in developing an understanding of the motion of bodies, Marey invented a number of devices that could record movements. His initial graphic methods enabled him to examine the way humans and horses walk, as well as how birds fly. Limitations to the tech- niques, however, moti- vated Marey to consider different approaches, and he was intrigued by the possibility of adapting the nascent photography methods of the period to meet the needs of his scientific research. At the time, Eadweard Muybridge had already begun his photographic experiments involving horses in motion, and when Marey saw his images in the journal La Nature in 1879, he began a correspon- dence with the photographer. Marey asked Muybridge to apply his technique to the flight
of birds but was unsatisfied by the results he obtained. Some of the most questionable aspects that Marey found in Muybridge’s work involved his basic setup, which consisted of a series of cameras that were placed parallel and adjacent to the subject’s path of movement. Marey realized that the use of a different camera to record each image meant that there was no single point of reference from which changes in position could be assessed. Moreover, accurately measuring the gaps of time between movements was problematic and, therefore, the representation of motion that was achieved was incomplete. Over the next twenty years, Marey carried out a series of efforts to correct these perceived shortcomings and to make the photography of motion a more scientific endeavor.
44 By 1881, Marey was a professor at the College de France and
was provided enough funding to establish a laboratory dedicated to physiological research. In this new setting, he developed a variety of investigative methods, the most basic of which involved recording multiple images of a subject’s motions on a single camera plate. Over time he refined this technique and was capable of taking 12 pictures per second using a photographic “gun,” which looked similar to a rifle and is commonly considered the first movie camera. Following the release of improved photographic film by George Eastman in 1885, Marey was able to vastly increase the photographic gun’s exposure speed to 60 images per second, greatly improving the quality of his motion pictures and essentially laying the foundations of modern cinematography.
Ignazio Porro (1801–1875)
Ignazio Porro’s primary contribution to optics was an
innovative prism image erecting system that is commonly used in binoculars and stereomicroscopes, though he also invented and improved a number of other scientific instruments. Today Porro is oſten considered to have been ahead of his time in many ways. Te Italian engineer received little acclaim or monetary compensation for his innovative devices, which only came to be fully appreciated and widely utilized aſter his death. In fact, when Ernst Abbe attempted to patent binoculars containing his own prism erecting system in 1893, the physicist was very surprised to find that someone else had invented and patented the design decades earlier. Despite his own intense work in the field of optics, Abbe had never heard of the inventor, a telling indication of Porro’s difficulties. Porro was the son
of an Italian engineer- lieutenant and, like his father, joined the military, serving initially as a cadet in the artillery and working his way up to a major in the reserve before he retired from service in 1842. Troughout many of his years in the military, Porro surveyed lands and developed improve- ments for the geodetic
doi:10.1017/S1551929510000428
www.microscopy-today.com • 2010 September
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