The Polytechnic had prepared for a full house. Miriam Aldbury, the events coordinator, had added thirty standing places behind the last row of Founders’ Hall, bringing capacity to 310. By ten minutes past seven on Tuesday evening, every seat and every standing place was taken. Another forty or fifty stood in the corridor outside the open doors, craning to hear.

Dr Emmeline Furness — lecturer in urban history at the Polytechnic, assessor of the Meredith letters discovered behind a false wall panel on Harker Street in March — stepped to the lectern at 7:34 PM with a leather folder, a set of photographic slides, and the quiet authority of a woman who has been living inside someone else’s handwriting for a month.

The first hour was meticulous. Furness walked the audience through letters thirteen through eighteen of the Josiah Meredith correspondence — personal letters from the textile merchant to his brother in Caldwell, written between September 1860 and February 1861. The handwriting deteriorated as autumn advanced. Meredith’s concerns narrowed: his workforce was thinning, his shipments were late, his foreman had not come in for three days.

Then, in letter sixteen, dated 14 November 1860: “The same affliction as last year’s visitation has returned. Three men on the quay this morning could not stand.”

The hall went still.

“We have known about the 1859 fever for a hundred and sixty years,” Furness said. “It is in the public record — the mortality returns, the emergency Poor Law expenditures, the council minutes. What we did not know, until these letters, is that it came back.”

The implications, as Furness laid them out, are considerable. The 1859 outbreak has long been understood as a single epidemic — severe, but contained and resolved. Meredith’s letters suggest something different: an endemic disease, cycling through a population that had not recovered from its first encounter.

Letter seventeen contains what Furness called “the most significant single document in the collection.” It is not a letter at all, but a pen-on-linen architectural drawing — a plan of the original quay layout, drawn in Meredith’s hand, showing the location of a hastily erected fever ward. The ward sat behind the easternmost grain shed, approximately forty metres from the present-day Bramblegate Steps.

The location matters. As Furness noted, it sits directly above the route of the Lower Conduit — the buried waterway mapped by Pella Strand earlier this year.

“We now have a fever ward and a freshwater conduit in the same location,” Furness said. “I am not a physician and will not speculate on the epidemiological implications. But the proximity is notable.”

Strand, who was in the audience, was seen writing in a notebook.

The lecture drew its largest response not from the fever evidence itself but from what Furness said at the end. Twenty-two letters remain unassessed. The final letters in the sequence are dated 1862 and 1863. Meredith died in 1871. There may be references to a third outbreak, or to public health measures, or to the conduit itself.

“We are not at the end of what these letters can tell us,” Furness said. “We are perhaps a third of the way through.”

Leonard Hewitt, a retired mathematics teacher of 74, was first in the queue. He has researched the 1859 fever independently for thirty years, using parish burial records from St Cuthbert’s and St Anne’s.

“I always suspected there was a second wave,” he told this newspaper. “The burial records show a spike in November and December of 1860 that I could never explain. Now I can.”

Hewitt approached Furness after the lecture and offered his research — three folders of transcribed parish data.

“She took them,” he said. “She took all three.”

The Heritage Committee was represented in the audience. The Committee is currently considering a heritage listing for the Lower Conduit system, on the basis of Strand’s 60-page survey report. Furness’s findings — linking the conduit’s route to the location of a fever ward, and to a previously unknown epidemic — will strengthen the case considerably.

The next lecture in the series is Professor Aldous Nettleford of Caldwell on the Greymoor geothermal system, Tuesday 15 April.