Although immediately popular and available without patent restriction from the very beginning, the daguerrotype was not the only photographic medium announced in 1839.
William Henry Fox Talbot, an amateur scientist in England had corresponding with his friend and colleague, the scientist Sir John Herschel (1792-1871), about their mutual discovering using the camera obscura and Lucida, and their experiments with light sensitivity.
In January 1839, stirred to action by the announcement of Daguerre’s invention, Talbot announced the development of his “photogenic drawings”.
On January 25 1839, he exhibit his early experiments at the Royal institution in London. A month later he published the complete instructions of his process.
Within time, the long exposures of the initial attempts were considerably reduced by the higher sensitivity of the plates, so Talbot introduced the “Calotypes” (derived from the Greek words Kalos, beauty and typos, sketch, line), patented in 1841.
Unlike the daguerrotype, the Calotype process utilized a single image from which multiple positive prints could be made. This process would become the basis for photography as we now know it.
General differences between a Daguerrotype and a Calotype image:
Daguerrotype: crisp clarity / printed on a polished wet plate

Calotype: soft focus / print on paper

In 1844, Talbot published “The Pencil of Nature” the first major book to be illustrated with 24 original photographs on plates.

Plate II in the volume was “Views of the Boulevards in Paris” made from the window of his hotel room.
“The spectator is looking Northwest, the time is the afternoon. The sun is just quitting the range of the buildings adorned with columns: its facade is already in shade, but a single shutter standing open projects far enough forward to catch a glimpse of sunshine. The weather is hot and dusty and they have just been watering the road…”

Independently of each other, Daguerre and Talbot found out the art of fixing upon metal and upon paper the light of the sun. In Talbot’s own words:
“The picture..is but a succession or variety of stronger lights thrown upon one part of the paper, and of deeper shadows on another. Now light, where it exists, it can exert an action”
Reference: Bibliography: A history of Photography
2 Thoughts on 1839: Talbot and the paper negative