It is often asserted that the Scottish reformer, educator, and pastor, Thomas Chalmers (1780-1847), was one of the originators of the so-called "Genesis Gap Theory" as a part of his effort to harmonize the ideas of evolution and creation. Scan the internet and you'll see this claim repeated again and again. Even many of the most reputable Intelligent Design or Creation Science sites perpetuate this peculiar notion.
It has no real substance however. Indeed, it is an "urban myth."
The actual origin of the "ruin-reconstruction" view of Creation comes from the writings of late 19th century writers like Hugh Miller, G.H. Pember, and I.T. Taylor. It was then popularized by early 20th century dispensationalists such as A.C. Dixon, A.J. Gordon, and H.A. Ironside. And it was particularly propounded in the best-selling study Bibles of Finis Dake and C.I. Scolfield. The theory asserts that some indeterminate amount of time elapsed between the first two verses of the Genesis narrative--this "gap" could then account for millions of years of geologic time or the fall of Satan or any number of other perceived textual difficulties.
There is no record of Chalmers endorsing this view--or anything like it. The notion that somehow he did comes from a single statement in a single lecture out of the more than fifty volumes of his writings.
This is what Chalmers actually said: “The detailed history of creation in the first chapter of Genesis begins at the middle of the second verse.”
Clearly, Chalmers posited no gap, no ruin and reconstruction, and no attempt to reconcile evolution and creation here. At most, he made a simple exegetical observation that Genesis 1:1 declares God's ex nihilo creation; Genesis 1:2a introduces the Spirit's moving amidst the material void; And Genesis 1:2b begins to unfold the details of that glorious moving and its resultant redolence.
Regardless, debates about the age of the earth and possible conflict with the historicity of the Bible would actually not come into common discourse until well after the death of Chalmers. Indeed, he made his isolated comment in 1815--long before Darwin ignited the controversy with the publication of "Origin of Species" in 1859.
Thomas Chalmers most assuredly wrestled with ways to find a common ground for scientists and theologians--his Astronomical Discourses were particularly effective examples of his apologetic methodology. But never would he compromise the integrity of Biblical truth for the sake of scientific accommodation.