Figure 1 – Caselli’s “Pantelegraph” from the German wikipidia and in the public domain. erman Wikipidia, original source: Die gesammten Naturwissenschaften, Dritte Auflage, In drei Bänden, Erster Band, Druck und Verlag von G. D. Bädeker, 1873, Seite 855 unten, Bild

My reason for discussing analogue vs. digital signals was to put us in a position to explore the early methods for transmitting images across telegraph and telephone lines. All of these early processes were analogue in nature. This means that a voltage is created at the transmitting side and this voltage is converted back on the receiving side to intensity on a surface.  Indeed, it is always a two sided process.  There has to be a means, on the transmitting side, to convert the intensity on the paper to a voltage and, on the receiving side, back to an intensity.

In addition, while the processes of telegraphy and telephony are intrinsically linear – a series of dots and dashes as a function of time or the voice translated to voltage as a function of time, images are intrinsically two dimensional.  Therefore, there needs to be an intrinsic scanning element at both ends, so that the two dimensional image can be properly translated.

The first, system for transmitting images was developed by Giovanni Caselli (1815-1891) in the mid 1850’s.  His “pantelegraph” was demonstrated by no less than French physicist Alexandre-Edmond Becquerel (1820-1891) to the French Academy of Sciences in 1858 (the year of the first transatlantic cable).  The “pantelegraph” is, arguably, more of a facsimile (FAX) machine than an image transmitter.  It copied small handwritten documents (111 mm x 27 mm) of up to 25 words, which it could do in 108 seconds.  For the most part it was used to transmit signatures and, therefore, to verify checks.  Never-the-less the concept of image transmission was born with the “pantelegraph.”

Figure 2 – an example of a Caselli “pantelegram,” from the Wikimediacommons and in the public domain.

The signature or other writing was drawn on a metal plate with insulating ink.  A pendulum driven scanner scanned an electrode or stylus across the plate and the current between the plate and the stylus was measured.  Wherever there was writing the current would drop.  This was converted to a voltage that was transmitted across the telegraph line.  On the receiving side, paper impregnated with potassium ferricyanide was used.  The process was reversed.  Whenever current flowed across the paper the potassium ferricyanide would darken.

In November of 1860, Caselli demonstrated the “pantelegraph” along a special line between Paris and Amiens.  Caselli successfully transmitted the signature of opera composer Gioachino Rossini (1792-1868) over the 140 km distance. The first “pantelogram was subsequently transmitted from Lyons to Paris on February 10, 1862.

One sees in this the absolute brilliance and creativity of nineteenth century engineers and scientists.  They dwelt in an analogue world, and it presented no limitations.

* I want to thank a Facebook reader for making me aware of Caselli’s “pantelegraph.”  I was going to start with photograph.  But this is an important part of the story.

Figure 1 – The ship that lay the 1866 transatlantic cable, The Great Eastern, at Hearts Content. From the Wikicommons and in the public domain.

We talk about the internet as a new invention, something born of the twentieth and twenty-first centuries.  However, if you think about it and the recognize that the essence of the the internet is not in the computer but is its role as a communications network, joining people on a world-wide web or net, the name of Samuel F. B. Morse (1791-1872), artist and daguerreotypist, immediately arises as the true inventor.

Samuel Morse, invented the telegraph and the Morse code.  On May 24, 1844 along a cable strung between Washington, DC and Baltimore, MD, Morse sent the message: “WHAT HATH GOD WROUGHT.”  The internet was born.

The dream of connecting the United States and Europe evolved between 1854 and 1866 with the laying of the first transatlantic cable by Cyrus West Field and the American Telegraph Company.  On August 16, 1858, the first message was sent from the United States on behalf of President James Buchanan: “GLORY TO GOD IN THE HIGHEST; ON EARTH, PEACE AND GOODWILL TOWARD MEN.” The rate of transmission was painful (2 min. per character or 0.1 words per min.).  Queen Victoria’s letter congratulations back to President Buchanan took sixteen hours to transmit.

The original cable deteriorated extremely rapidly.  Speed of transmission became slower and slower.  Three weeks after the first transmission engineer Widman Whithouse attempted to increase transmission speed by increasing the signal voltage and blow the cable out.  Investor enthusiasm plummeted, and it took another eight years to successfully lay a new cable and restore the system.  This new cable proved long-lasting and, perhaps of equal significance, in the intervening time overland cables had been laid in both Europe and the United States.  Indeed the transcontinental cable in the United States, which united the east and west coasts on October 24, 1861, made the legendery Pony Express obsolete, and it shut down the next day.  With the completion of the transatlantic cable, Europe and the United States were interconnected with what was truly the first internet.

The effect was transformative.  Even with steam ships it took two to three weeks to transmit information by letter between New York and the European capitals.  With the transatlantic cable this communications time was reduced to three minutes.  That’s over ten thousand fold!

The first internet was the wired telegraph.  This followed by wireless telegraphy, wired telephony, and radio. I leave television out, because television largely functioned one way.   Finally we have our current internet, which took the concept to a whole new level by uniting computers or central processing units.  The internet became more than a way of rapid communication, but became a place to store, access, and disseminate information (real, false, and imagined). We have spoken previously about the first image on the modern internet, the image of “Les Horribles Cernettes,”.  But before that came the first transmission of images over telegraph and telephone lines.  How this was done and indeed the underlying nature of transmitting this kind of information is a fascinating one that we we will take up next.

Figure 1 – Daguerreotype of Samuel Finlay Breeze Morse, artist, inventor, photographer, 1845. From the library of Congress and in the public domain.

I have spoken before about S. F. B. Morse (1791-1872), his introduction of the daguerreotype to American, and the birth of the modern world.  I have been reading David McCullough‘s interesting history of nineteenth Americans and their physical and intellectual journeys to France, “The Greater Journey, Americans in Paris.”  McCullough quotes Morse’s letter to his brothers describing the moment in which he first sees Daguerre’s invention.  I thought that I would share it with you.

“They are produced on a metallic silver-coated [copper] surface, the principal pieces about 7 inches by 5 [inches], and they resemble aquatint engravings, for they are simple chiaroscuro, and not in colors.  But the exquisite minuteness of the delineation cannot be conceived.  No painting or engraving ever approached it.  For example: In a view up the street, a distant sign would be perceived, and the eye could just discern that there are letters upon it, but so minute as not to be read with the naked eye.  By the assistance of a powerful lens, which magnified fifty times, applied to the delineation, every letter was clearly and distinctly legible, and so also were the minutest breaks and lines in the walls of buildings and the pavements of the streets.  The effect of the lens upon the picture was in a great degree like that of a telescope in nature.”

We read in this the encounter of the nineteenth century intellect with the new world that photography represented.  This was truly a seminal moment, and the beginning of a new world perspective.  Truly the dawn of the modern.