Allan George Bromley (1 February 1947 – 16 August 2002) was an Australian historian of computing who became a world authority on many aspects of early computing and was one of the most avid collectors of
mechanical calculator
A mechanical calculator, or calculating machine, is a mechanical device used to perform the basic operations of arithmetic automatically, or (historically) a simulation such as an analog computer or a slide rule. Most mechanical calculators wer ...
s.
[Graeme Philipson]
Allan Bromley: historian, eccentric, gem
27 August 2002.
The work on understanding
Charles Babbage
Charles Babbage (; 26 December 1791 – 18 October 1871) was an English polymath. A mathematician, philosopher, inventor and mechanical engineer, Babbage originated the concept of a digital programmable computer.
Babbage is considered ...
's calculating engines is Allan Bromley's greatest legacy. The October–December 2000 issue of the ''
IEEE Annals of the History of Computing
The ''IEEE Annals of the History of Computing'' is a quarterly peer-reviewed academic journal published by the IEEE Computer Society. It covers the history of computing, computer science, and computer hardware. It was founded in 1979 by the AFIPS ...
'' was dedicated to him for the quality of his research on this subject.
[
His studies of the ]Antikythera mechanism
The Antikythera mechanism ( ) is an Ancient Greece, Ancient Greek hand-powered orrery, described as the oldest example of an analogue computer used to predict astronomy, astronomical positions and eclipses decades in advance. It could also be ...
, in collaboration with Michael T. Wright, led to the first working model of this ancient analogue computer
An analog computer or analogue computer is a type of computer that uses the continuous variation aspect of physical phenomena such as electrical, mechanical, or hydraulic quantities (''analog signals'') to model the problem being solved. In ...
.
Bromley was an associate professor
Associate professor is an academic title with two principal meanings: in the North American system and that of the ''Commonwealth system''.
Overview
In the ''North American system'', used in the United States and many other countries, it is a ...
at the University of Sydney
The University of Sydney (USYD), also known as Sydney University, or informally Sydney Uni, is a public research university located in Sydney, Australia. Founded in 1850, it is the oldest university in Australia and is one of the country's si ...
. His main academic interest was the history of computers
History (derived ) is the systematic study and the documentation of the human activity. The time period of event before the invention of writing systems is considered prehistory. "History" is an umbrella term comprising past events as well ...
. He died of Hodgkin's lymphoma
Hodgkin lymphoma (HL) is a type of lymphoma, in which cancer originates from a specific type of white blood cell called lymphocytes, where multinucleated Reed–Sternberg cells (RS cells) are present in the patient's lymph nodes. The condition wa ...
.
Biography
Bromley was born on 1 February 1947 and named after his uncle Allan, who was killed in New Guinea
New Guinea (; Hiri Motu
Hiri Motu, also known as Police Motu, Pidgin Motu, or just Hiri, is a language of Papua New Guinea, which is spoken in surrounding areas of Port Moresby (Capital of Papua New Guinea).
It is a simplified version of ...
during World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
, and his father George, who died on 8 August 1962. Bromley grew up on a property at Freeman's Reach, on the Hawkesbury River
The Hawkesbury River, or Hawkesbury-Nepean River, is a river located northwest of Sydney, New South Wales, Australia. The Hawkesbury River and its associated main tributary, the Nepean River, almost encircle the metropolitan region of Sydney. ...
, in New South Wales
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, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
, Australia, in an historic home, "Sunny Corner". He completed his secondary education at Richmond High School and in 1964, at the age of 17, his academic ability earned him a scholarship to study science at the University of Sydney
The University of Sydney (USYD), also known as Sydney University, or informally Sydney Uni, is a public research university located in Sydney, Australia. Founded in 1850, it is the oldest university in Australia and is one of the country's si ...
. He had been awarded the Nuclear Research Foundation Medal, University of Sydney, Summer Science School, 1963.
Bromley graduated in 1967, with first-class honours in physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...
, and stayed on for a research degree in astrophysics
Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline said, Astrophysics "seeks to ascertain the nature of the h ...
He was awarded his PhD in 1971. His doctoral work on maser
A maser (, an acronym for microwave amplification by stimulated emission of radiation) is a device that produces coherent electromagnetic waves through amplification by stimulated emission. The first maser was built by Charles H. Townes, Ja ...
emission from interstellar gas clouds required extensive computation with high-order polynomial
In mathematics, a polynomial is an expression consisting of indeterminates (also called variables) and coefficients, that involves only the operations of addition, subtraction, multiplication, and positive-integer powers of variables. An exa ...
s, and awakened his interest in computing.
Bromley had an amateur interest in the history of mechanical inventions, and was aware of the ancestral figure of Charles Babbage
Charles Babbage (; 26 December 1791 – 18 October 1871) was an English polymath. A mathematician, philosopher, inventor and mechanical engineer, Babbage originated the concept of a digital programmable computer.
Babbage is considered ...
. No one had ever made a very detailed study of Babbage's papers and, in a surprising career move, Bromley decided to turn historian, and took a year's sabbatical leave in 1979 to work on the Babbage Papers at the Science Museum
A science museum is a museum devoted primarily to science. Older science museums tended to concentrate on static displays of objects related to natural history, paleontology, geology, industry and industrial machinery, etc. Modern trends in mu ...
in London. What he found was overwhelming: notebooks containing over 6,000 pages of Babbage's impenetrable scribblings, 300 machine drawings, and several hundred notations. They were to occupy Bromley for the next several years. His first marriage, to Jann Makepeace, was during this time. Bromley convinced the Science Museum in London that Babbage's Difference Engine No. 2
A difference engine is an automatic mechanical calculator designed to tabulate polynomial functions. It was designed in the 1820s, and was first created by Charles Babbage. The name, the difference engine, is derived from the method of divided ...
, which had been designed between 1847 and 1849, could be built and, from 1989 to 1991, it was.
After Babbage's engines, Bromley moved on to other historical computing artefacts. He made a ground-breaking study of the Antikythera Mechanism
The Antikythera mechanism ( ) is an Ancient Greece, Ancient Greek hand-powered orrery, described as the oldest example of an analogue computer used to predict astronomy, astronomical positions and eclipses decades in advance. It could also be ...
, originally made famous by the Yale
Yale University is a private research university in New Haven, Connecticut. Established in 1701 as the Collegiate School, it is the third-oldest institution of higher education in the United States and among the most prestigious in the wor ...
historian Derek de Solla Price
Derek John de Solla Price (22 January 1922 – 3 September 1983) was a British physicist, historian of science, and information scientist. He was known for his investigation of the Antikythera mechanism, an ancient Greek planetary computer, and ...
in the late 1950s. Price had speculated that the mechanism, dating from 50 BC, was an astronomical calculating device. Bromley's background in astrophysics paid dividends, and after several trips to Athens where he obtained radiograph
Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnostic" and "therapeut ...
s of the inner mechanisms, and with the help of a clockmaker Frank Percival, back in Sydney, they produced a working reconstruction. In November 2000, Bromley was given a Distinguished Service Award and made an Honorary Associate of the Powerhouse Museum
The Powerhouse Museum is the major branch of the Museum of Applied Arts & Sciences (MAAS) in Sydney, the others being the historic Sydney Observatory at Observatory Park, Sydney, Observatory Hill, and the newer Museums Discovery Centre at Castle ...
, Sydney.
In 1998, after a long spell of illness, he was diagnosed with Hodgkin's lymphoma
Hodgkin lymphoma (HL) is a type of lymphoma, in which cancer originates from a specific type of white blood cell called lymphocytes, where multinucleated Reed–Sternberg cells (RS cells) are present in the patient's lymph nodes. The condition wa ...
. He met Anne Mitchell at that time and, on 15 April 2000 they married. He died on 16 August 2002.
Collections
Bromley started collecting mechanical calculators in 1979. A year later he already had sixty pieces. Eventually he was responsible for a collection of old computers which used to be displayed in the rear foyer of the building containing the University of Sydney
The University of Sydney (USYD), also known as Sydney University, or informally Sydney Uni, is a public research university located in Sydney, Australia. Founded in 1850, it is the oldest university in Australia and is one of the country's si ...
Computer Science
Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to Applied science, practical discipli ...
Department. At home, he had a large personal collection of mechanical calculator
A mechanical calculator, or calculating machine, is a mechanical device used to perform the basic operations of arithmetic automatically, or (historically) a simulation such as an analog computer or a slide rule. Most mechanical calculators wer ...
s, slide rule
The slide rule is a mechanical analog computer which is used primarily for multiplication and division, and for functions such as exponents, roots, logarithms, and trigonometry. It is not typically designed for addition or subtraction, which is ...
s, and the like. He was a generous donor of artefacts to museums in Australia, especially the Powerhouse Museum
The Powerhouse Museum is the major branch of the Museum of Applied Arts & Sciences (MAAS) in Sydney, the others being the historic Sydney Observatory at Observatory Park, Sydney, Observatory Hill, and the newer Museums Discovery Centre at Castle ...
in Sydney, and the Australian Computer Museum Society Inc.
His collection included some rare pieces. The pride of place was taken by four mechanical anti-aircraft gun predictors developed and built by the British government after World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
. The machines, weighing about half a tonne, marked the height of mechanical computation; they were first used in the Spanish Civil War
The Spanish Civil War ( es, Guerra Civil Española)) or The Revolution ( es, La Revolución, link=no) among Nationalists, the Fourth Carlist War ( es, Cuarta Guerra Carlista, link=no) among Carlists, and The Rebellion ( es, La Rebelión, lin ...
and extensively during World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
. They performed in real-time and were capable of predicting the firing angle to explode a shell within 10 meters of a plane at anything up to 10,000 meters.
Charles Babbage's computing engines
Part of Allan Bromley's scholarship was his study, at the Science Museum
A science museum is a museum devoted primarily to science. Older science museums tended to concentrate on static displays of objects related to natural history, paleontology, geology, industry and industrial machinery, etc. Modern trends in mu ...
library in London, of the original drawings for the Difference Engine
A difference engine is an automatic mechanical calculator designed to tabulate polynomial, polynomial functions. It was designed in the 1820s, and was first created by Charles Babbage. The name, the difference engine, is derived from the method ...
and Analytical Engine
The Analytical Engine was a proposed mechanical general-purpose computer designed by English mathematician and computer pioneer Charles Babbage. It was first described in 1837 as the successor to Babbage's difference engine, which was a des ...
designed by Charles Babbage
Charles Babbage (; 26 December 1791 – 18 October 1871) was an English polymath. A mathematician, philosopher, inventor and mechanical engineer, Babbage originated the concept of a digital programmable computer.
Babbage is considered ...
more than a century earlier. These studies and the most detailed analysis and interpretation led to the reconstruction of two Difference Engines No. 2 under the direction of Doron Swade:
Antikythera mechanism
Bromley built a partial reconstruction of the Antikythera mechanism
The Antikythera mechanism ( ) is an Ancient Greece, Ancient Greek hand-powered orrery, described as the oldest example of an analogue computer used to predict astronomy, astronomical positions and eclipses decades in advance. It could also be ...
, one of the oldest (surviving) gear
A gear is a rotating circular machine part having cut teeth or, in the case of a cogwheel or gearwheel, inserted teeth (called ''cogs''), which mesh with another (compatible) toothed part to transmit (convert) torque and speed. The basic pr ...
ed mechanisms known. Working with Frank Percival, a Sydney clockmaker, he improved on an earlier reconstruction by Derek J. de Solla Price
Derek John de Solla Price (22 January 1922 – 3 September 1983) was a British physicist, historian of science, and information scientist. He was known for his investigation of the Antikythera mechanism, an ancient Greek planetary computer, an ...
. Having tested Price's theory using Meccano
Meccano is a brand of scale model, model construction system created in 1898 by Frank Hornby in Liverpool, England. The system consists of reusable metal strips, plates, Structural steel#Common structural shapes, angle girders, wheels, axles and ...
parts, Bromley found that the mechanism was unworkable. Working with Percival, he improved the device by altering the function of the handle so that one complete rotation would correspond to a single day, which he considered to be the most obvious astronomical unit. Bromley worked with the same set of parts as Price, but suspected that a gap in the mechanism was originally home to several extra gears.
Another breakthrough by Bromley concerned a train of gearing which appeared to have 15 and 63 teeth, for which Price had been unable to discover a purpose. Price considered these numbers to be too difficult to work with, and assumed that they should be corrected to 16 and 64, theorising that it could have operated a four-year cycle on the device. Bromley worked with the original count of 15 and 63 teeth, discovering that the train's cycle was four and a half years; four of such cycles equalled 18 years, a duration equal to the cycle of eclipse
An eclipse is an astronomical event that occurs when an astronomical object or spacecraft is temporarily obscured, by passing into the shadow of another body or by having another body pass between it and the viewer. This alignment of three ce ...
s. With this gearing, the mechanism worked correctly, with the pointer moving into a new square for each new moon, as the handle is turned, meaning that each square on a dial represented one month. Over 223 months, or 18 years, the complete cycle is shown.
The model was acquired by the Museum of Applied Arts & Sciences
The Powerhouse Museum is the major branch of the Museum of Applied Arts & Sciences (MAAS) in Sydney, the others being the historic Sydney Observatory at Observatory Hill, and the newer Museums Discovery Centre at Castle Hill. Although often de ...
in early 2017.
References
Sources
*
{{DEFAULTSORT:Bromley, Allan
1947 births
2002 deaths
University of Sydney alumni
University of Sydney faculty
Australian computer scientists
Historians of science
People associated with the Science Museum, London
Deaths from cancer in New South Wales
20th-century Australian historians