A Brief History of Blackboards and Slates

My career in education began with the use of chalk and a blackboard, transitioned into a room with only dry erase marker boards, and finished in a class with only an electronic smart board. Except for the few times I was inconvenience by a projector bulb picking a bad moment to go bad (and if a chalk board had been available, I would have been grateful) I loved the improvements that each transition brought to my ability to more effectively convey my ideas.
But for the period from 1800 to 2000 few things were as ubiquitous in a mathematics classroom as the blackboard. Today modern "white boards" may have taken their place in many institutions, or even an electronic version called a smart board; but board work still seems to be a part of the current classroom procedure. In a recent talk, Keith Devlin began by saying, "I step back from the (now largely metaphorical) blackboard and .. "
Whatever the present state of its demise, the classic chalkboard was so common a classroom presence that it was part of a frequently repeated gag sequence on the popular Simpsons cartoon series.(Not sure if the use shown above could be termed "educational")

It appears that the blackboard first came into American education around 1800. The National Museum of American History website on colonial education says,:

"Mathematics teachers with ties to England and France introduced blackboards into the United States around 1800. By the 1840s, these erasable surfaces were used for teaching a wide range of subjects in elementary schools, colleges, and academies. The Massachusetts educator William A. Alcott visited over 20,000 schoolhouses. “A blackboard, in every school house," he wrote, "is as indispensably necessary as a stove or fireplace."

James Pillan, a Scottish teacher and education reformer is often cited as the "inventor" of the blackboard, but this seems to be a misunderstanding based on a letter from Pillan which appeared in Jeremy Bentham's Chrestomathia (1815). It was entitled Successful application of the new system to language-learning, and dated 1814; it mentions the use of chalk and blackboard in teaching geography. But Pillan only began teaching in 1810, almost a decade after the board made its way to America, and as we shall see, literally hundreds of years too late to "invent" the chalkboard.  He may, however, be the inventor of colored chalk. He is reported to have had a recipe with ground chalk, dyes and porridge.

Blackboards and slates were seemingly used well before any of the previous examples in musical study. In Composers at Work, author Jessie Ann Owens devotes several pages to the existence of several types of slate and wood "cartella" which were used to write out musical ideas. She describes the discoveries of these with five or ten line staves dating to the 16th century. Much larger wall size examples seem to have been used but have only been confirmed by iconography. The book includes an image from a woodcut by Hieronymus Holtzel of Nuremberg in 1501.

An even earlier use of chalk and chalkboards comes from ALBERUNI'S INDIA,

AN ACCOUNT OF THE RELIGION, PHILOSOPHY, LITERATURE, GEOGRAPHY, CHRONOLOGY, ASTRONOMY, CUSTOMS, LAWS AND ASTROLOGY OF INDIA ABOUT A.D. 1030.  On page 182 we find, "They use black tablets for the children in the schools, and write upon them along the long side, not the broad side, writing with a white material from the left to the right."

In America they seem to have very quickly become and essential part of daily school life. [From a web page of Prof. Rickey]

Perhaps no one method has so influenced the quality of the instruction of the cadets as the blackboard recitations. Major Thayer (Superintendent from 1817) insisted on this form, although old records show that it was introduced at West Point by Mr. George Baron, a civilian teacher, who in the autumn of 1801 gave to Cadet Swift "a specimen of his mode of teaching at the blackboard." Today it is the prominent feature in Academic instruction. [Quoted from Richardson 1917, p. 25] There is indication that the blackboard was used in a few schools in the US before it was used at USMA. See Charnel Anderson, Technology in American Education, 1650-1900, published by the
US Dept of Health, Education, and Welfare 1961(I have read this document and he credits Frenchman Claude Crozet with introducing the blackboard to the USMA and that he built and painted one to teach his classes.  It may well be that after Baron left under a cloud in 1802, the method was not used by other teachers there until Crozet arrived in 1817. 

Thayer had visited the Ecole Polytechnique in France to study their methods and was heavily influence by the "French" method when he became superintendent, even to the point of extending instruction in French so that the students could better master the French texts in advanced math.. I can't find an early example of the use of chalk or slate in France, but they seem to have been very much a part of the educational process by the time Galois threw an eraser at his examiner in July of 1829.

Galois was not the only one who reacted negatively to some of the innovations in education connected to the blackboard. At Yale, there were two "rebellions" in which students refused to accept some changes in testing practice. Here is a paragraph from Stories in Stone: Travels Through Urban Geology By David B. Williams.

This "rebellion" occurred in 1830, with 43 rebels expelled, including Andrew Calhoun, the son of John C Calhoun, and Alfred Stillé, who eventually did get a degree from Yale and another from  U of Pennsylvania before he became a somewhat famous doctor, and one of the first to distinguish Typhus from Typhoid fever. His rebellious side wasn't limited to college however, as he refused to accept germ theory and laboratory medicine. There had been a similar event in 1825 at Yale, but those students recanted and were readmitted.

One of the earliest mentions of blackboards I have found has nothing to do with education, however. It seems that a custom developed in London's financial district in the later part of the 18th century to list the names of debtors on a blackboard to shame them into paying, and it seems to have persisted for a long time. Here is a description of the practice from Chronicles and Characters of the Stock Exchange
By John Francis, Daniel Defoe; printed in 1850.

From Wikipedia I learned that the Oxford English Dictionary provides a citation from 1739, to write "with Chalk on a black-Board". I know it is common in England for Pubs to advertise with a blackboard outside their doors on the sidewalk, but have no idea how far back this idea originated.
 
Prior to the use of blackboards students learned their early lessons from an object called a hornbook. Here is a description of one from the Blackwell Museum webpage at Northern Illinois University

Paper was pretty expensive once and hornbooks were made so children could learn to read without using a lot of paper. A hornbook was usually a small, wooden paddle with just one sheet of paper glued to it. But because that paper was so expensive, parents and teachers wanted to protect it. So they covered the paper with a very thin piece of cow's horn. The piece of cow's horn was so thin, you could see right through it. That's why these odd books were called "hornbooks."

Hornbooks seem to have been totally imported from England into the American Colonies, and almost all had a cross on the upper left, with the Lord's Prayer at bottom.  The American Revolution seemed to have almost completely eliminated the import of Hornbooks in rejection of all things English at the time.  The education conversion to the blackboard seems to have finished the hornbooks very quickly afterward judging from this quote from the OED about Hornbooks, (a1842 HONE in A. W. Tuer Hist. Horn-Bk. I. i. 7) " A large wholesale dealer in..school requisites recollects that the last order he received for Horn-books came from the country, about the year 1799. From that time the demand wholly ceased..In the course of sixty years, he and his predecessors in business had executed orders for several millions of Horn-books".
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Early blackboards were usually made of wood, (but some may have been made of paper mache') and painted with many coats as true slate boards were very expensive. Schools purchased large pots of "slate paint" for regular repainting of the boards. The Earliest quotes from the OED date to 1823.

1823 PILLANS Contrib. Cause Educ.    A large black board served my purpose. On it I wrote in chalk. 1835 Musical Libr. Supp., Aug. 77 The assistant wrote down the words..on a blackboard. 1846 Rep. Inspect. Schools I. 147 The uses of the black board are not yet fully developed.

However under "slates" I found other  earlier uses. In "1698 FRYER Acc. E. India & P. 112 A Board plastered over, which with Cotton they wipe out, when full, as we do from Slates or Table-Books" which indicates that boards covered with Plaster or other materials were used to write upon much earlier than the earliest use of "blackboards" in classrooms.

Another early use of slates is given in David E. Smith's Rara arithmetica of a book printed in 1483 in Padua of the arithmetic of Prosdocimo containing a mention of the use of a slate. This led Smith to conclude that at this time the merchants would actually erase and replace numbers (as was originally done by the Hindu mathematicians working in their sand trays) in division rather than showing the cross-outs that distinguish the galley method of division after it was adopted to use on paper.

The very earliest claim for slates I have found is of use in the 11th century. A work called Alberuni's Indica (Tarikh Al-Hind), "They use black tablets for the children in the schools, and write upon them along the long side, not the broadside, writing with a white material from the left to the right."

Chalkboards became so important for teaching that teachers in the 19th century sometimes went to extremes to create one. In Glen Allen, Virginia; a school is named for Elizabeth Holladay, a pioneer teacher who started the first public school in the Glen Allen area of Henrico County at her home in 1886. On a note about the history of the school it says she had, "Black oilcloth tacked to another part of the shipping crate served as a blackboard." 

The slate was used even after paper became a relatively commonplace item. Many school histories report the use of slates into the 20th Century. This use may have been significant. The Binney & Smith company, better known to many for their creation of the Crayola Crayon, began the production of slate pencils, for writing on slate, in the year 1900. As an aside, they also won a Gold Medal at the St. Louis Fair.

Slate pencils prior to 1800 were known as Dutch Pencils in England, but increased slate mining in Wales around 1800 led to more domestic production, and use of slates, and slate pencils in England.   In the journal Australian Historical Archaeology, (2005) Peter Davies reports that in the excavation of a site called Henry Mill that was only operational from 1904 until around 1930 they found 30 slate pencils, remnants of four slates, and a single graphite pencil core. 

In "Slates Away!": Penmanship in Queensland, Australia, John Elkins, who started primary school in 1945, writes that he used slates commonly until around the third year of school.

I think in Prep 1 that we had some paper to write on with pencils, but my memory of the routine use of slates is much more vivid. Each slate was framed in wood and one side was inscribed with lines to guide the limits for the upper and lower extremities of letters. The slate "pencils" were made of some pale gray mineral softer than slate which had been milled into cylinders some one-eighth of an inch in diameter and inserted into metal holders so that about an inch protruded.
Each student was equipped with a small tobacco tin in which was kept a damp sponge or cloth to erase the marks. Sharpening slate pencils was a regular task. We rubbed them on any suitable brick or concrete surface in the school yard. Teachers also kept a good supply of spares, all writing materials and books being provided by the school. It is possible that the retention of slates stemmed from the political imperative that public education should be free.

Slates were advertised in newspapers in the US as early as 1737. Slates, as indicated above, show up as commonplace in quotes from the OED as early as 1698. It seems they may have been used for some artistic or educational purposes as early as the end of the 15th Century. In the famous painting of Luca Pacioli,
Ritratto di Frà Luca Pacioli, Pacioli is shown drawing on a slate to copy an example from Euclid in the open book before him. The closed book, which has the dodecahedron upon it, is supposedly Pacioli's Somma di aritmetica which was written in 1494.

In the Dec 2003 issue of Paradigm, the Journal of the Textbook Colloquium, is an article by Nigel Hall titled, "The role of the slate in Lancasterian schools as evidenced by their manuals and handbooks". A couple of snips from the article appear below:

The Oxford English Dictionary gives as its first citation for slate being used as a writing tool a quotation from Chaucer’s Treatise on the Astrolabe written about 1391. Whether usage began around this time or had begun much earlier is unknown, although as a technology it shared many characteristics with the wax tablet, used extensively from before the time of the Greeks until the 1600s in Europe, and even surviving in some usages until the early twentieth century (Lalou, 1989). Knowledge of the use of slate for writing after Chaucer is limited until one reaches the second half of the eighteenth century. The mathematician Digges (1591) refers to writing on slates and in the new colony of America an inventory (Plymouth Colony Archive, n.d.) made on 24 October 1633 of the possessions of the recently deceased Godbert and Zarah, noted among many items, ‘A writing table of slate’ (table here being a tablet of slate).

Hall goes on to suggest that, in fact, the use of slates may not have been very common in England until the end of the 18th Century because reading (beginning with hornbooks) was much more commonly taught than writing. He credits Lancaster for the promotion of slates for writing and math, but suggests that the slate was a principal element in the "monotorial system" in which more advanced students taught the lower group. An illustration showing the use of slates and the student monitor below is taken from the article. [See the full article here]

The blackboard was extended to some specialty uses as well. A "Slated Globe" was advertised in The New York Teacher, and the American Educational Monthly, Volume 6 in 1869 for use in spherical geometry and geography classes. A four inch diameter globe sold for $1.50

I also recently found this image on a Wikipedia article about Benjamin Pierce. He seems to be standing beside a stand with a spherical blackboard resting on it, but can not be sure that is what it was.

In an 1899 article for the proceedings of the Society for the Promotion of Engineering Education, Professor Arthur E Haynes of the University of Minnesota had an article for, "The Mounting and Use of a Spherical Blackboard, which included this image.

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Recently, J F Ptak posted an article on his Science Books blog from Scientific American, (Sep 13, 1890) about a pen-tip eraser for slate pens meant to be wetted to erase the marks on a slate by the pen.  The article described the invention with credit to the inventor, Mrs Emma C. Hudson