Mining recommenced in 1904, but was abandoned again in 1907, this time reputedly due to falling tin prices, though copper fell dramatically in 1907 as well.

In 1915 a calciner was erected, together with "another" Wilfley concentrating table and a 5-foot (1.5 m) Berdan crushing pan, and a new shaft was sunk on the tin deposit.

The new tin shaft had poppet legs erected over it in 1916, and a 16 hp Tangye winding engine and vertical boiler were installed.

In 1924 the furnace and part of the mill was leased by Arsenic Limited to O.C Roberts Limited, who remodelled the furnace to treat high-grade ore, as a result of the Prickly Pear Land Commission letting a 12-month contract for the supply of Roberts Improved Pear Poison, which was manufactured at Wallangarra.

[1] The tin mine area consists of the open cut, with a grided shaft in its floor, and a collapsed adit at the base of its work face.

The concrete pad supporting one of the poppet legs is inscribed with the names "T Fredrick, S. Lynn, F. Meehan, GRM Kane".

Adjacent to the shaft is a cutting dug into the wall of the benched area, which appears to have been used as a store or crib room.

On the other side of the shaft is a bench cut into the slope, with a "Herman" winding engine facing the poppet legs.

The flue, which is collapsed, was an above ground 1.8-metre (5 ft 11 in) wide vault tunnel, and approximately the 200-foot (61 m) length referred to in the literature.

At the other end of the flue from the furnace is a large brick pile and 14-metre (46 ft) long plume of rubble consisting of a fallen chimney.

The curve of the flue is supported on a platform built of stone, and a large number of 2.95-metre-long (9.7 ft) iron pipes lay scattered in this area.

[1] East of the furnace are a number of sleepers, lengths of wire cable, and the base of the structure which could be the flying fox used to bring tin and copper ore to the mill site.

A large amount of tailings sand lines the creek above the dams, leaching the metallic salts and having a strongly sulphurous smell.

The remains of the Merton Furnace and condensing flue are rare pieces of the technology demonstrating arsenic extraction in Queensland.

The combination of metals produced at the mine increases the potential of the site to contribute worthwhile research results.