[citation needed] In the shaft the ventilation was natural, driven by the higher temperature underground compared to above ground.

The open end of the adit had been connected to a sloping wooden chimney on the hillside, by which means the draught was increased.

After a new working was opened at the 75 fathom (450 feet (140 m)) level in 1873, a substantial discovery of rich silver ore was made.

The fire continued burning as long as oxygen was present; this produced carbon monoxide, which filled the lower parts of the shaft.

Those at the top got out without too much difficulty, but others arrived at the surface in a state of near collapse, and it soon became apparent that a large number of the miners who had made the descent were unable to return.

[1] Diving dresses arrived from Douglas[1] but were found to be of no use; however the pumps and hoses were of significant help, enabling the rescuers to take a supply of clean air with them into the shaft.

[1] Led by Captain Kewley[1] the rescuers went deeper into the shaft, where several dead bodies were found, however no effort was made to remove them as long as there was a chance of finding anyone alive.

[7] At the 115 fathom level the air was still deemed too poisonous for the rescuers,[7] as shown by the immediate extinguishing of candles lowered further into the shaft.

[7] The body of a miner was observed at the 130 fathom level; however the rescuers were unable to reach it because of the air,[7] and the search was again suspended.

Whilst trying to take an air sample at the 100 fathom level, Captain Kewley was overcome and had to be hauled back to the surface.

[8] The examination was carried out by the eminent physiologist John Scott Haldane, one of the foremost authorities on the causes of mining deaths due to gases.

Mouse lowered into the mine in a kibble as far as 130 fathom level, came tip[clarification needed] alive, but legs paralysed; killed on reaching the surface.

The carbon monoxide was in each case determined colorimetrically with blood solution, and the hydrogen by passing over a glowing platinum spiral.

The reason for the continued presence of the gas in the lower parts of the mine was found during a further investigation by Sir Clement Le Neve Foster.

[9] Leaving most of the miners at the 115 fathom level, Captain Kewley, Captain Reddicliffe and Dr Foster proceeded further down the shaft and reached a level about 10 ft (3.0 m) above the body of Robert Kelly in safety and lowered the testing apparatus with its candle alight,[9] where they could see the body of Kelly, lying in the position described by the Foxdale team during their previous descent.

[9] Captain Kewley and Clague volunteered to go down and get the body, but their request was refused by Dr Foster due to the carbon monoxide.

This action appeared to disturb the gas: Captain Kewley immediately began to feel unwell and had to be put into the kibble and taken to the surface.

[9] Foster and the rest of the recovery team who had stayed at the 115 fathom level also began to feel the effects of gas, and immediately returned to the surface.

[9] An inquest was opened at the Snaefell Mine on the afternoon of Wednesday 12 May, presided over by the coroner, Samuel Harris.

[8] It had been ascertained that carbonic oxide[clarification needed] occurred in certain rocks and minerals,[9] however such gas had never been found as a natural constituent of the atmosphere of mines.

[9] It was evident, therefore, that the deaths of the victims of the Snaefell disaster was due to carbon monoxide (CO), produced by timber burning in the mine.

At the time of the accident, it was common practice for miners to have a safety helmet with a candle held in its clay socket.

Once nearly burnt out, the miner would stick up the end against the side of his working place[clarification needed], whether timbered or not, take a fresh candle from his bundle, and light it from the flame of the old one.

[9] Careless miners would sometimes leave a candle end to burn away of itself, whilst in other cases the snuffing out could be imperfectly performed and the wick could go on smouldering, and eventually ignite inflammable material with which it was in contact.

[9] Once started upon a timber prop, the fire would have naturally spread to the adjacent supports, and would have continued to burn as long as plenty of air was available.

A meeting of the general committee of the Snaefell Mine Disaster Fund, presided over by the Lieutenant Governor of the Isle of Man, Lord Henniker was held on Monday 13 September 1897; it was announced that the Lieutenant Governor had been successful in obtaining for Captain John Kewley and Mr G. Williams under the Metalliferous Mines Regulation Act for the Inspection of Mines in the Isle of Man, the Medal of the Honourable Order of the Knight of St John of Jerusalem.

The medal was awarded for the "self-sacrificing exertion and distinguished bravery" displayed under the most trying and hazardous circumstances in their heroic efforts to save life and succour the helpless in connection with the disaster.

Governor Henniker was a Knight of Justice of the Honourable Order, and as such he had been requested to make the presentation on behalf of the Prince of Wales.

Following a substantial rock fall in the shaft in 1908 it was decided that the clearance of the debris would prove to be uneconomical and the mine was closed.

[12] Spoil residue was tipped into an automatic sieve and in turn fed into an 80-ton Ball mill which the company had sourced from the Gold Coast.