Benjamin Franklin
This portrait, which depicts Franklin as a learned scientist and
inventor, was one of his favorites. Pictured on the left is the signal-bell
apparatus Franklin devised to detect the presence of electrically-charged
clouds. The bolt of lightning , seen through the open window, became
an attribute closely identified with Franklin. At Franklin's death
French philosopher/scientist Jacques Turgot wrote: "He seized
the lightning from the sky and the scepter from the hand of tyrants."
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Edward Fisher (1730-ca. 1785), after Mason Chamberlin (d. 1787)
Benjamin Franklin of Philadelphia, 1763
Mezzotint
Prints & Photographs Division (32)
LC-DIG-ppmsca-10083
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Benjamin Franklin
An Account of the New Invented Pennsylvanian
Fire-Places.
Page 2
Philadelphia: Printed and Sold by B. Franklin, 1744
Rare Book & Special Collections
Division (35)
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The Franklin Stove
Franklin wrote this description of the stove he had invented to
promote sales of a model being manufactured by his friend Robert
Grace. A series of partitioned iron plates permits a continuous supply
of fresh warm air, separated from the smoke, to be distributed equally
throughout the room. By controlling the airflow, less heat is lost,
and much less wood is needed. Franklin's stove became so popular
in England and Europe that this essay was frequently reprinted and
translated into several foreign languages. |
Franklin's Design for Bifocals
Benjamin Franklin is credited with the invention of bifocal glasses,
which he sketched here for his friend George Whatley, a London merchant
and pamphleteer. Franklin told Whately he found them particularly
useful at dinner in France, where he could see the food he was eating
and watch the facial expressions of those seated at the table with
him, which helped interpret the words being said. He wrote: "I
understand French better by the help of my Spectacles."
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Benjamin Franklin to George Whatley
(ca. 1709-1791), May 23, 1785
Letterpress manuscript
Manuscript Division (36)
Partial Transcription |
Benjamin Franklin.
Experiments and Observations on Electricity,
made at Philadelphia in America, By Benjamin Franklin.
Page 2
London, Printed for David Henry, 1769
Rare Book & Special Collections
Division (37A)
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Experiments in Electricity
In 1751, Peter Collinson, President of the Royal Society, arranged
for the publication of a series of letters from Benjamin Franklin,
1747 to 1750, describing his experiments on electricity. Franklin
demonstrated his new theory of positive and negative charges, suggested
the electrical nature of lightning, and proposed a tall, grounded
rod as a protection against lightning. These experiments established
Franklin's reputation as a scientist, and in 1753 he received the
Copley Medal of the Royal Society for his contributions to the knowledge
of lightning and electricity. |
On Electricity
Benjamin Franklin's formulation of a general theory of electrical "action" won
him an international reputation in pure science in his own day. Writing
to Dutch physician and scientist Jan Ingenhousz, Franklin responds
to a number of his friend's questions about electricity and the Leyden
jar, an early form of electrical condenser. In this draft scientific
report, it appears that Franklin wrote his answers first using dark
ink, leaving room for the questions, which he wrote in red ink.
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Benjamin Franklin
"Queries from Dr. Ingenhousz, with my Answers,
B.F."
Page 2 - Page
3
Holograph report with annotations, [1777]
Enlarged version: Page 1 - Page
2 - Page 3
Manuscript Division (38)
Partial Transcription |
Benjamin Franklin to Jan Ingenhousz,
1777
Manuscript essay
Enlarged version
Manuscript Division (39)
Partial Transcription |
Franklin Explains the Effects of Lightning
In this lengthy essay intended for his fellow scientist Jan Ingenhousz,
Benjamin Franklin attempted to explain the effects of lightning on
a church steeple in Cremona, Italy, by describing the effects of
electricity on various metals. He based his hypothesis on other written
accounts, and used this sketch of a tube of tin foil to aid in his
explanation. |
Mapping the Gulf Stream
Although Spanish explorers had described the Gulf Stream, Franklin,
fascinated by the fact that the sea journey from North America to
England was shorter than the return trip, asked his cousin, Nantucket
sea captain Timothy Folger, to map its dimensions and course. Franklin
published this map and his directions for avoiding it in the Transactions
of the American Philosophical Society in 1786. Systematic research,
conducted by the U.S. Coast Survey, of the Gulf Stream did not occur
until 1845.
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Benjamin Franklin
"Maritime Observations
and A Chart of the Gulph Stream"
in Transactions of the American Philosophical Society. Philadelphia:
1796
Engraved map
Geography & Map Division (40A)
[gmd9/g9112/g9112g/ct000136]
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Benjamin Franklin
"Hints concerning what is called Catching
a Cold," [1773]
Page 2
Manuscript document
Enlarged version: Page 1 - Page
2
Manuscript Division (41)
Partial Transcription |
Franklin Battles the Common Cold
Despite his eminence in scientific circles, Benjamin Franklin remained
concerned with the more practical applications of scientific study.
This sheet entitled "Definition of a Cold" is one of a
series bearing Franklin's notes for a paper he intended to write
on the subject. Exercise, bathing, and moderation in food and drink
consumption were just some of his steps to avoid the common cold. |
The Aurora Borealis
Benjamin Franklin's interest in the mystery of the "Northern
Lights" is said to have begun on his voyages across the North
Atlantic to England. He ascribed the shifting lights to a concentration
of electrical charges in the polar regions intensified by the snow
and other moisture. He reasoned that this overcharging caused a release
of electrical illumination into the air. In this essay, which he
wrote in English and French, Franklin analyzed the causes of the
Aurora Borealis. It was read at the French Académie des Sciences
on April 14, 1779.
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Benjamin Franklin (1706-1790)
"Suppositions and Conjectures on the Aurora
Borealis," [ca. December 1778]
Page 2 - Page
3 - Page 4
Manuscript essay
Enlarged version: Page 1 -Page
2 - Page 3 - Page
4
Manuscript Division (42)
Partial Transcription |
L'Armonica: Lettera del Signor Beniamino
Franklin al Padre Giambatista Beccaria, Regio Professore di Fisica
nell' Univ. di Torino.
Page 2
[Milano?:1776?]
Rare Book & Special Collections
Division (43)
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Franklin's Armonica
Before leaving London in July 1762, Franklin wrote to the Italian
philosopher Giambatista Beccaria. Not having anything new to report
on their shared interest in electricity, Franklin described the improvements
he had made to the musical glasses invented by Richard Puckeridge.
By fitting a series of graduated glass discs on a spindle laid horizontal
in a case and revolving the spindle by a foot treadle, Franklin could
create bell-like tones by touching his wet fingers to the revolving
glasses. Franklin's armonica became popular in Europe, with Mozart
and Beethoven composing music for it. |