by the time of the fourth meeting of the wiq, held on wednesday, 12 june 1912, the institute had its own room at the imperial chambers and frequency of meetings had been reduced to fortnightly. there were only about 30 members present, including a few ladies. rockwell delivered an interesting lecture on "magnetic wave action," during which he explained, and advocated, the use of silicon detectors. it was foreshadowed tha mr balsillie would deliver a lecture to members during his visit to brisbane, but it appears that this did not eventuate.