The ridge is brighter than it has ever been, and the instruments to measure it are finally on their way.

Dr Odette Collis recorded the forty-second consecutive night of the Greymoor Highland luminous phenomenon from her observation point above Dunvale on Sunday evening. The greenish-white glow, which she first documented on 3 February, is now approximately 25 per cent brighter than her initial observation — a steady, unbroken intensification that has not reversed or plateaued on any recorded night.

“The rate has been remarkably constant,” Dr Collis said. “Roughly half a per cent per night, compounding. The source is stable, consistent, and growing. I have no framework for predicting when or whether it will level off.”

The spectral signature remains unchanged: ionised nitrogen and trace sulphur dioxide, consistent with superheated gases venting through fractured rock from a subsurface geothermal source. Professor Elara Whitstone of the Royal Institute has described the phenomenon as “a geothermal system of unknown scale revealing itself through the ridge.”

On Monday, the Royal Institute awarded the monitoring station equipment contract to Northcroft Instruments of Edgeminster, one of three firms that submitted tenders before the Saturday deadline. The contract, valued at 195,000 florins for construction and initial equipment, covers three broadband seismometers, two atmospheric gas sampling units, a meteorological mast, a photometric array for continuous glow measurement, and an insulated wind-rated shelter.

Gerald Northcroft, the firm’s managing director, confirmed that fabrication would begin immediately. “We can have the seismometers and gas samplers ready for installation by mid-April,” he said. “The photometric array requires calibration against Dr Collis’s existing measurements. We’ll need her notebooks.”

Collis, who has filled forty-three observation notebooks since 2015, indicated that she would make them available.

Station construction at the site — approximately 800 metres northwest of the old meteorological outpost, above the central emission zone — is expected to begin in early April, with the station operational by mid-May. It will be the first permanent scientific presence on the Greymoor ridge since the 1950s meteorological outpost was abandoned.

Gareth Penn, the sheep farmer at Highfield Farm three miles south of the central emission zone, has been watching the glow from his kitchen window since February. He reported on Monday that two of his border collies have taken to sleeping indoors, though he attributes this to the late-March cold rather than the glow.

“The sheep haven’t changed their behaviour,” Penn said. “The dogs have, but dogs are more theatrical than sheep.”

The deep geological survey — 250 metres depth, 1.65 million florins — will begin once the monitoring station is operational. Its findings will be critical not only for understanding the phenomenon but for assessing the viability of copper mining expansion in the Greymoor Highlands, where the mapped extent of the geothermal system overlaps with the zones containing the most promising deep deposits.

Dr Collis will return to the ridge tonight. She has not missed an evening since 3 February.