An Original Theory or New Hypothesis of the Universe, from 1750

English astronomer Thomas Wright is best known as the man who first hypothesized that clusters of stars in the sky might actually be other galaxies, and that the luminous blur of the Milky Way was an optical illusion that could be used to prove our place within that galaxy.

Or, as he wrote in An Original Theory or New Hypothesis of the Universe in 1750:

…the many cloudy spots, just perceivable by us, as far without our Starry regions, in which tho' visibly luminous spaces, no one star or particular constituent body can possibly be distinguished; those in all likelihood may be external creation, bordering upon the known one, too remote for even our telescopes to reach.

Nearly 150 years after Wright's death, the Hubble telescope would prove him right about the Milky Way, at least.

An Original Theory or New Hypothesis of the Universe is a series of 9 letters written by Wright to a nameless friend, in which he expands upon his theories of creation and the universe. The collection of letters was accompanied by 32 engravings that depicted his interpretations of the cosmos. From Public Domain Review:

The thirty-two "graven and mezzotinto" plates found at the end of An Original Theory — printed "by the Best Masters" and likely based on Wright's drawings — reveal his remarkable range of vision. The most simple images show what Wright has observed in the night sky (Plate XVI), then diagrams of how these constellations (Plate XIX) and comets (Plate IX) are arranged and understood. From his empirical observations, and deductions about what this must mean for the relative positions and orbits (Plate XXII), Wright develops a much more ambitious proposal as to the construction of the universe. Plate XXVII depicts a globe within a globe, part of his hypothesis on the patterns and rules followed by bodies in space. It's a hypothesis which culminates in his globular visions of the last two plates, which show full and section views of "the Object of that incomprehensible Being, which alone and in himself comprehends and constitutes supreme Perfection". The extraordinary, endless eyes of the final plate (XXXII) give a good sense of Wright's cosmic conclusion, that just as the solar system as we observe it is full of complex bodies, so too, but on a larger, parallel scale is the wider universe: an "unlimited plenum of creations", all centred on the law and vision of God.

Here's a sample of some of his work:

"A Representation of the Convexity, if I may call it so, of the intire Creation, as a universal Coalition of all the Stars consphered round one general Center, and as all governed by one and the same Law".
"You may if you please, call a partial View of Immensity, or without much Impropriety perhaps, a finite View of Infinity".
"The Object of that incomprehensible Being, which alone and in himself comprehends and constitutes supreme Perfection".
"Geometrical Scale to all the primary Parts of the visible Creation, with regard to the Distance of Orbits of Mercury, Saturn and Syrius, compared with the Globe of the Sun."

There's kind of a heliocentric golden ratio Fibonacci vibe going on here, as far as the Earth relates to the sun to relates to the cosmos relates to the entirety of God—but even that was pretty radical for the time. And Wright obviously made some impressive galactic observations.

Thomas Wright's An Original Theory or New Hypothesis of the Universe (1750) [Public Domain Review]