In 1827, the road passing through the tomb was widened and deepened. To achieve this, workmen removed two of the sarsens from the revetment kerb and placed them in the corner of the wood to the south of the monument. In the early 1840s, the Reverend Beale Post conducted investigations into the Medway Megaliths, writing them up in a manuscript that was left unpublished; this included Addington Long Barrow and Chestnuts Long Barrow, which he collectively labelled the "Addington Circles". Thomas Wright recorded that in 1845 a local parson, the Reverend Lambert Blackwell Larking, dug into a chamber at Addington, discovering "fragments of rude pottery". From the context in which Wright wrote, it seems that Addington Long Barrow is referred to, although it remains possible that Chestnuts was the barrow in question. In the early 1860s, Charles Roach Smith visited the site alongside Charles Warne and Charles Moore Jessop, the latter of whom described it as a "Celtic" monument in a subsequent article for "Gentleman's Magazine".