The Papers of Joseph Henry

Sample Documents

Dust jacket
From the dust jacket.

Below, in chronological order, is a small sampling of documents we have transcribed, edited, and published in The Papers of Joseph Henry. The sample includes Henry's first surviving letter, an entry from his laboratory notebooks as well as one from his European diary, a letter Henry wrote to a newspaper editor about lightning rods, and a student's view of Henry as a teacher. Also included are letters touching on two of his scientific breakthroughs (in understanding the principles of electromagnetism and the electromagnetic telegraph in particular). A letter to his wife reveals the domestic side of Henry.

Click on facsimile of Henry letter
Facsimile, Henry to parents.

In addition to reading our transcriptions and accompanying editorial notes, you may also wish to see an electronic image of the original manuscript. Just click on the word "facsimile" at the end of each transcription. You will be taken to an image that is best for printing (a 100-200KB file); click on the image to see a larger one (200-400KB) for viewing on the web.

We hope this sample stimulates interest in Henry and gives some sense of the value of primary sources for understanding history. For a classroom exercise, teachers may wish to have their students fill out the document analysis worksheet provided here. For an excellent web site on using archival documents in the classroom, see the National Archives and Records Administration's "Digital Classroom."

Editorial Remarks: 1) We have revised the text of the original editorial notes to make them more suitable for this sample. But we wish to remind readers to consult the appropriate volume of The Papers of Joseph Henry for fuller context. 2) Some of our editorial conventions changed in the course of producing the volumes. For example, in the early volumes, Henry's and other author's deletions were italicized and enclosed in angled brackets, as in <deleted words>. Beginning with volume 7, strikeouts were used, as in deleted words. Another example: in the early volumes, the editors silently brought interlineations (words added by the author, usually above the line) into the line; beginning with volume 7, interlineations were represented by up and down arrows. In the samples below, they are represented, beginning with the document from volume 7, by being superscripted, as in added word or words. Also note that in the document from volume 7, superscripted capital letters are used to designate text notes (on, for example, the author's alterations or physical aspects of the paper or ink) that appear at the end of the document. A full explanation of our editorial policy is given in the front matter to each volume under the heading "Notes on Style."

Below is the earliest Joseph Henry letter we have found. Henry was ten years old at the time of writing. He was living in Galway, New York, some thirty-six miles from his parents in Albany. Though the poor grammar and misspellings are Henry's own, a characteristic he would only partially overcome with practical experience, the stilted language of the text came from the standard letter he followed.


Galway [New York]
July 26, 1808          

Honoured father & Mother
    I embrace this Oppertunity to write to you to inform you that I am well at this period Like wise Granmother and all the rest of my Relitives, and I flatter my self that these few Lines will find you enjoy-ing your healths, and my brother & sister it is a general time of health here. I endeavour to Make the best improvement in my Learning that I posibly can though at the first it seemed a Little irksome and hard, and I hope to gain the point at Last--pray Dear parents accept of my most humble duty to your selves and kind Love to my Brother & sister. I subscribe myself hoping You will look over the blots from your son,

Joseph Henry

Henry Papers, Smithsonian Archives. Published in Nathan Reingold et al., eds. The Papers of Joseph Henry, vol. 1, December 1797-October 1832: The Albany Years (Washington, 1972), pp. 3-4.

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When Henry penned the letter below, he was virtually unknown outside the scientific community of Albany, New York, where he was professor of mathematics and natural philosophy at the Albany Academy. The letter resulted in his first major publication, "On the Application of the Principle of the Galvanic Multiplier to Electro-Magnetic Apparatus, and Also to the Developement of Great Magnetic Power in Soft Iron, with a Small Galvanic Element," in the January 1831 issue of Silliman's Journal. In this article, Henry announced a significant breakthrough in constructing powerful electromagnets--"then the equivalents of our atom smashers, computers, and rockets," as Nathan Reingold has put it. The article would bring Henry to the attention of the international scientific community and establish his reputation as a leading American scientist.


Albany Dec 10th 1830

Prof. Silliman
    Dear Sir
    I have been engaged for some time past in a series of experiments on electro-magnetism and particularly in reference to the developement of great magnetic power with a small galvanic element. The results I wish to publish if possible in the next No. of the Journal of Science. I am anxious that they should appear as soon as possible since by delaying the publication of the principles of these experiments for nearly two years I have lately had the mortification of being anticipated in part by a paper from Prof. Moll in the last No of Brewster's Journal.3
    Please inform me if I shall be too late for the next no. of the Journal if I send my paper within two weeks of the date of this letter--it will probably make five or six pages. If it be not too late I should like to have a small wood cut of a powerful magnet which I am constructing on electro-magnetic principles.
    Both Mrs. Henry and myself retain a lively reccollection of the many polite attentions we received in New Haven last Spring. We join in a respectful remembrance to your self and family.

I am with much respect
Your humble serv          
Joseph Henry                

Silliman Family Papers, Manuscripts and Archives, Yale University Library. Published in Nathan Reingold et al., eds. The Papers of Joseph Henry, vol. 1, December 1797-October 1832: The Albany Years (Washington, 1972), pp. 301-302.

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Henry gave the title "Record of Experiments" to his laboratory notebooks, which are preserved in three large manuscript volumes among his papers at the Smithsonian Archives. The entries begin in 1834, when Henry was professor of natural philosophy at the College of New Jersey (later Princeton University), and continue through 1863. They are an invaluable resource for understanding how a physical scientist of the nineteenth century actually worked. The entries recorded failures, as in the example below, as well as successes.


May 11 [1835]

Sketch of battery

Exp 1 Two batteries arranged as one. The coil with 60 feet copper ribbon inch & ½ wide gave greatest snap.5 When hands were placed to connect the extremities of coil no shock. When iron vice was brough[t] to the side of the copper of the battery & connected with the end of the coil brilliant scintilations6
Sketch of battery

Exp 2 The current passed through a galvanic magnet no increased effect perceived in the spark--current passed in the opposite direction no increased effect.

Exp 3 Passed the current through the large magnet and afterwards around it so as to magnetize the iron at the <same> instant of making the contact or demagnetize it at the instant of breaking the circuit. Small spark. Experiment not satisfactory must be tried again7

Henry Papers, Smithsonian Archives. Published in Nathan Reingold et al., eds. The Papers of Joseph Henry, vol. 2, November 1832-December 1835: The Princeton Years (Washington, 1975), p. 392.

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The entry below is from the diary Henry kept of his first trip to Europe. He conceived of his diary chiefly as a scientific and technical record. His tour lasted from March to October 1837, and he met many of the leading scientists in Britain, France, and Belgium. This entry concerns his visit with British polymath Charles Babbage, whose famous calculating machine was a precursor of the computer.


April 3rd [1837] Went with Prof Wheatstone9 to see Mr Babage.10 Was ushered into the house of the Professor by a servant in livery.
    Found Mr B a very plesant person much younger in appearance than I had anticipated. Appeared not more than 40 although he has a son grown up and engaged in the business of an engineer.11
    We were informed (Prof. Bache12 and my self) that the celebrated calculating machine was to be exhibited to Mr Hume13 the radical member of parliament from Middlesex and his Brotherinlaw14 who is about to sail for america.
    The principal object of the request that the machine might be exhibited at this time is that the Brotherinlaw of Mr. Hume might know something of the machine before visiting America as he had been informed that every person comming from England would be required to explain the machine.
    Before the company arrived Mr B took us into an other room apparently his work shop to explain to us the general principles of a new machine15 of which he is now making the drawings and which will far transend the powers of the first machine16 even were it compleeted according to the original plan.
    The explanation given us was confined to the modus applicandi of the machine and to some very general principles of action. This machine is divided into two parts one of which Mr B calls the store house and the other the mill. The store house is filled with wheels on which numbers are drawn. These are drawn out occasionally by levers and brought into the mill where the processes required are performed. This machine will when finished tabulate any formula of an algebraic kind. It will also calculate the numerical value of an integral when the same is expressed approximately by an infinite series. Besides calculating all Logarithmetic functions it also will be of great use in calculating the mean results of astronomical and meterological observations.
    Before Mr B had finished his exposition the important person Mr Joseph Hume the member from middlesex his Daughter17 and his Brotherinlaw were anounced. We then adjourned to an upper parlor where the machine partly finished is placed.
Sketch of computing machine
It is contained in a glass case about 2½ feet high 18 inches wide and 8 inches thick on the face where the figures are exhibited. It resembles something like the anexed figure and presents four cylenders of wheels. On these ie the periphery of the wheels numbers are painted. I should have said that each colum or cylender is composed of 4 wheels thus figured.
    The operation of calculating by this instrument is by an application of the principle of differences. For an account by Dr Lardner see Edinburgh Review No 120.18 The machine of which Mr B is now making the drawings is of a totally different nature and operates on interely different principles.
    We were favoured by a most admirable exposition of the use of the machine and of its importance in producing perfect accuracy without the possibility of committing an error.

Henry Papers, Smithsonian Archives. Published in Nathan Reingold et al., eds. The Papers of Joseph Henry, vol. 3, January 1836-December 1837: The Princeton Years (Washington, 1979), pp. 224-226.

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The letter below on lightning rods illustrates Henry's concern over the exaggerated claims of some inventors and his impatience with non-scientists who ventured into scientific waters. Henry had been studying various aspects of lightning, including its conduction through lightning rods. In the 1840s, his advice would be sought on protecting the U.S. Capitol Building in Washington and Independence Hall in Philadelphia from lightning.

[August 1, 1838]19


Mr Editor20
    You published a few days since a certificate signed by a number of highly respectable gentlemen in favour of an improved modification of the lightning rod,21 invented by Dr King22 of Boston. The certificate states, that the principal feature in the new rod consists in its presenting points to the atmosphere, in all directions &c.
    We have no personal knowledge of Dr King and would be sorry unjustly to disparage his invention yet a sense of duty to the Public compells us to state, that the new modification of the rod, appears to us not founded on sound philosophical principles.
    In the first place, it is a well established fact, that, a single point becomes much more highly electrified and consequently acts at a much greater distance than a ball under the same circumstances; or than a point in the vicinity and under the influence, of other points. These considerations appear to have induced the French Philosophers to reccommend but one point at the upper end of the rod.23
    Again, a number of points, along the course of the rod, would as it appears to us tend to give off the electricity; and thus produce dangerous consequences from the lateral action of the discharge.
    With these views, until some new principle be discovered in Electricity, we shall adhere to the well known form of the conductor reccommended in a report to the French Academy of Sciences in 1824 by Poisson, Fresnel, Gay Lussac and others.
    One word in reference to the highly respectable names attached to the certificate. We would say that in all ordinary matters we would pay them sincerely due defference but in the present instance, endorsing an improvement in science, they loose with us a little of their wonted influence.24


(Private note)
   I have long intended to commence furnishing you from time to time with some small contributions in the way of science.26 I have however constantly thought myself too much engaged in other matters. If you can decipher the scrawl please give the article on the other leaf a place in your paper. It is intended as much for the gentlemen who have signed the certificate as for Dr King.27

With Respect & Esteem
In haste yours              

One word in reference to the <highly respectable> opinions of the highly respectable Gentlemen who have signed the certificate. These in all ordinary matters would be received by us with due respect and attention but in the present instance endorsing a scientific invention we do think they lose a little of their wonted influence.

Draft, Henry Papers, Smithsonian Archives. Published in Nathan Reingold et al., eds. The Papers of Joseph Henry, vol. 4, January 1838-December 1840: The Princeton Years (Washington, 1981), pp. 81-83.

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Samuel F. B. Morse's development of the telegraph owed much to Henry's research in electromagnetism during the 1830s (see article on Henry and Morse). Morse used the letter below to help plead his case before the U.S. Congress for adoption of his telegraph, and Henry wrote it with that purpose in mind. But the letter is also the first instance of Henry's oft-repeated statement that Morse deserved credit not for priority of conception, but rather for the ability to realize an efficient system of telegraphy. This point would be of crucial importance later in Morse's legal travails over telegraph patents, as would be the interpretation of this letter.


Princeton29 Feby 24th 1842

Professor Morse
Dear Sir
    I am pleased to learn that you have again petitioned congress in reference to your telegraph and I most sincerely hope that you will succed in convincing our Representatives of the importance of the invention. In this however you may perhaps find some difficulty, since in the minds of many, the electro-magnetic telegraph is associated with the many chimerical projects constantly brought before the Public30 and particularly with the schemes so popular a year or two ago for the application of electricity as a moving power in the arts. All schemes for this purpose, I have from the first asserted, are premature and formed without proper scientific knowledge.31 The case however is entirely different in regard to the electro-magnetic telegraph the science is now fully ripe for such an application <of its principles>, and I have not the least dout, if proper means be afforded, of the perfect success of the invention.32 The idea, of <the transmission of> transmitting intelligence,33 by the electrical action has been suggested by various persons from the time of Franklin to the present but until within the last few years or since the discoveries34 in electro-magnetism all attempts to reduce it to practice were necessarily unsuccessful. The mere suggestion however, of a scheme, of this kind is a matter for which little credit can be claimed, since it is one which would naturally arise in the mind of almost any person familiar with the phenomena of electricity; but the bringing it forward at the proper moment when the developments of science can furnish the means of certain sucess and <the> to <devising of a> devise plans for putting <the scheme> it into practical operation <offred> are the grounds of a just claim to scientific reputation as well as to public patronage.
    About the same time with yourself Professor Wheatstone of England and Dr Steinheil of Germany proposed plans of the electro-magnetic telegraph but these differ almost as much from your's as the nature of the common principle will permit and unless some essential improvements have lately been made in the European plans I should prefer the one invented by yourself.35 With my best wishes for your success I remain

With much Respect & Esteem36
<I am as ever>Yours Truly      
Joseph Henry                            

Draft, Henry Papers, Smithsonian Archives. Published in Nathan Reingold et al., eds. The Papers of Joseph Henry, vol. 5, January 1841-December 1843: The Princeton Years (Washington, 1985), pp. 150-151.

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Although Henry's skills as a research scientist brought him a measure of fame, during his years at Albany and Princeton he was first and foremost a teacher. And judging from contemporary letters, diaries, and student notebooks, he was an outstanding one, beloved and respected by students for his knowledge, sense of humor, and willingness to discuss issues outside the curriculum. The diary entries below by a senior at Princeton give us a starry-eyed glimpse of "Professor Henry."


Tuesday, March. 3rd [1846].
...Had a long conversation with Prof. HENRY at the Bookstore this morning.... He is a splendid old fellow to talk with--he affects no superiority over the smallest, is free & familiar & social--but "for a' that", there is that about him--an indescribable Je ne sais quoi--which excites within one, an emotion akin to Awe! I always feel as if I were in the presence of a Superior Being--infinitely far above me or my hopes of future being. He amused me in his talk about the German Metaphysics, by his manner of telling a story of a
Dutch Savan & Yankee Numskull.
The Philosopher had been talking Transcendentalism to a Beotian38 headed Yankee who couldnt coincide with him for sheer lack of comprehension. At last, after exhausting every endeavor at elucidation, he exclaimed in despair--"GOT forgive Christopher Columbus for discovering America!!!"...

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Thursday. May 28th [1846]
Today constitutes an Epoch in the Annals of the present Junior Class--no less than their Hegira from the sterile land of Mathematics & their Entry into the Beulah of Philosophy! They have now become Shepherds in the Delectable Mountains & what not that is pleasant in their Pilgrim's Progress through this Scholastic Valley of the Shadow of Death! They began their course on Physique this aftn... HENRY introduced himself to them in his usual manner. I met the old Prof. today--he was very cordial--asked me where I had been & gave me a license to attend his new course of lectures. The old Fellow is a Walking Awe to me--a Peripatetic Superstition! I dont know the littleness of my own being until I am thrown into his company & then the Lilliput of my Mind crouches before the Brobdignag of His! I feel as though I were in the Presence of awful disembodied Intellect & my puny Insignificancy fairly writhes before the mighty nervousness of the Presence! Upon JOHNNY & the Rest of the Faculty for whom I entertain not the "shadow of a shade" of Respect--upon them I can poke out my Face from the "Toga Virilis" of Alumnusship & feel Ease & Equality with them even in the inferiority of my Mind & my Knowledge. They are Men who have nothing within them to command with--and as soon as the tawdry Robe of their Executive Authority is torn from them--their whole Character is dishevelled. There is no Nerve--no firm, independent Nerve about them! All their Dignity lies in their Casual Station. They are mere "[?Tutors] of the Minnows"--whining through hollow Pipes of a petty Jurisdiction to the Tune of their own Tomfoolery! A Murrain ever rest on their defunct Tyrrany!--& a Star ever shine on the head of Nassau's Nobleman--the Great & Wise HENRY!!...

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Monday. June. 1st 1846.
...HENRY lectures to the Juniors again this morning & I again attend. His manner grows more & more interesting, every time he lectures. He grows upon you. There's no popping up & then popping out about him. He isnt a kind of Water Pot that thro' a number of small holes allows his Instructions to filter through & drizzle out on the Understandings of his Pupils--but he is a Great Canal--laugh not at the Simile--like a Canal in its Constancy Uniformity, Depth & Majesty of Flow. Or like his own Galvanism--a Strong & Constant & Powerful Current--not possessing the momentary pungency & the Rapid Brilliancy of Electricity is true, but having that which it has not, a Continuity & a Deep Power in it that lasts & lasts with strong Effect....

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General Manuscripts Bound, Manuscripts Division, Department of Rare Books and Special Collections, Princeton University Library. Published in Marc Rothenberg et al., eds. The Papers of Joseph Henry, vol. 6, January 1844-December 1846:The Princeton Years (Washington, 1992), pp. 387-388; 425-426; 430.

When Henry became secretary of the newly created Smithsonian Institution in December 1846, he retained his position at the College of New Jersey until June 1848. During this period, Henry divided his time between Washington, D.C., and Princeton, where his wife, son, and three daughters remained until January 1848. Lonely and under tremendous pressure in his new position, Henry often poured out his feelings in letters to his wife Harriet. These letters provide us with insights into his family life as well as documentation about his various initiatives in the early days of the Smithsonian. As can be inferred from the letter below, Harriet was less than enthusiastic about the family's pending move to the nation's capital.


Washington wednesday 
morning 7 o'clock 1847
May 5                           

My Dearest
    I have written to you every day since my arrival and therefore this is my fourth epistle I hope you will receive the whole number though they contain nothing of importance. I say nothing of importance meaning thereby of interest to any Person but yourself for I am happy in beleiving that every thing however, trifling which relates to me, is of high importance to you. And though it is impossible that I should appear in your physical eyes quite as great and as faultless a man as I may in the mental vision of those who have only heard of me from a distance yet I feel assured and rejoice in the assurance that I am very dear to you and that you are even more tenderly and anxiously attached to me on account of the faults of character which must be glaringly exhibitid to one in as close communion with me as you are. I was in my early life exposed to many temptations and I can never be sufficiently thankful that I have been preserved as I have been. "You may love me for the dangers that I have escaped and I will love you for pitying them."
    I think the transfer to Washington when once it is made will be much less disagreeable than you immagine.40 YouA as well as myself will be roused to greater effort-- Your time and thoughts have been for several years past engrossed necssisarily with the whole care of the Family the physical and moral developement of our children,41 but as they grow older their intellectual faculties wil require more attention. You will be called on to devote with them considerable time to reading and mental operations which will rouse your energies in the direction in which they you are well qualified to excell. Mary will soon be old enough to take an interest in works of a higher order than those which now occupy her attention-- She wll read to you while you are sewing and your comments will as they do now but in a higher degree expand her mind. We must endeavour to get for our little Girls a Governess in the Family--if possible a Lady of good education, accomplished maners and of a good heart and temper. Mary requires a good deal of attention as to her carriage & her personal habits as to ease of action--Helen will require less of this and Carry least of all; she is a Lady born. The substratum foundation and the material of the character of each is admirable and they only require a little attention as to the embellishment. Will. I presume will be much pleased with the expected visit of Richard.42 I must take him more under my charge and perhaps I can do this more effectually by carrying him with me when I travel we will then be more thrown together and a more free communication established.
    I am now going to the Treasury office and shall not return until 3 O'clockB when I may perhaps scribble a few more lines. I start for home this evening or in the early train tomorrow. I expect to be in Princeton on Friday but should I not arrive until saturday do not be uneasy-- For a time adieu--
    Just through dinner--was quite hungry spent the morning in the west part of the city visited J. Q. Adams43 in his 80th year remarkable memory related several interesting annecdotes of history-- Exhibited to him my plans of the Smithsonian Institution with which he was pleased.44 I promised to furnish him with a copy-- I shall not be able to get off until tomorrow morning.
    The day has been warm but plesant the spring is quite late for this place though vegetation is much perhaps I should say considerably farther advanced than in Princeton. I [...]C my letter to Mrs Ludlow yesterday so that she will be prepared for my arrival tomorrow.
    I hope to find you very much better on my return and shall be much disappointed if I do not receive the accustomed greeting inD the entry when I enter the door. Give my kind regards to Mary Ann LaGrange45E and thank her for the use of her watch it has done me good service. I was however obliged to purchase a key for the article.
    Kiss all the children for me and receive the unnecessary assurance that I am as ever


A. Altered from A
B. 3 O'clock altered from 12
C. Hole in paper.
D. Altered from on
E. Altered from Lagrange

Family Correspondence, Henry Papers, Smithsonian Archives. Published in Marc Rothenberg et al., eds. The Papers of Joseph Henry, vol. 7, January 1847-December 1849:The Smithsonian Years (Washington, 1996), pp. 102-104.

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