ENGINEERS’ INSTITUTE

New Zealand Times, Volume XXXVIII, Issue 8757, 12 June 1914, Page 10

ENGINEERS’ INSTITUTE

‘ LECTURE ON HEAT.

Under the auspices of the Wellington branch of the Australasian Engineers’ Institute, an educative and interesting lecture was given by Mr A. McVicar, at the institute’s hall last evening. The subject of the lecture was “Heat.” Mr J. Rankine occupied the chair, and there wore about thirty present.

The lecturer laid it was very difficult to say definitely what heat really was. There were various definitions given of heat, perhaps the simplest being: “Heat is a form of energy” or the agent which produces the sensations of hotness, warmth, coldness, and similar sensations. Quoting Maxwell; the speaker said the molecules of all bodies were in a state of continual agitation. The hotter the . body was Humore violent were its molecules agitated. -The temperature of a body was its condition respecting heat as it affected the senses. Many young engineers were apt to get mixed with the terms “heat” and “temperature.” Temperature was a state, or condition, and just as water flowed from a high to a low level, heat flowed from bodies in the form of temperature. Heal and temperature were analogous ' to water and “level.” The effects ot heat on bodies generally were:— (1) Change'of volume —that was, bodies generally expanded by the application of heat; (2) heat'changed the state of a body from a solid to a liquid, or from a liquid to a gas; and (3) heat raised the .temperature. Mr McVioar then stated that there were three kinds of heat, sensible, latent, and total heat, and gave a comprehensive demonstration of the more technical points of this complex, though interesting, subject. Mr McVioar received a most .(attentive hearing, and at the conclusion of the lecture a vote of thanks was accorded him.