“I have tested the ‘Shaw’ gas governor which you forwarded out of stock, in the various circumstances under which gas is ordinarily consumed, and I pronounce it to be a satisfactory and trustworthy instrument in every respect.
“The pressure of gas in the mains is usually in excess of the average requirements of consumers, owing to circumstances over which the gas authorities have no control.
“The lower the pressure at which gas is consumed, the smaller the consumption and the better the light, provided the pipes and the pressure are sufficient to admit of the required volume of gas passing to the burners.
“Regulation by means of a stop tap at the meter, or near to the burner, is impossible owing to the varying pressures during the hours of consumption, and hence the need of a regulator or governor which will adapt itself automatically to the changing conditions.
“Shaw’s governor performs that function with certainty and constancy.
“With a series of ordinary burners, regulated by the ‘Shaw’ governor the consumption of gas per hour was 28 cubic feet, and each one gave an illuminating power equal to 15·25 standard sperm candles; whereas with the same burners, consuming the same gas, but ungoverned, the consumption was 33·8 cubic feet per hour, and each gave an illuminating power of 13·7 standard candles.
“The governed burners were then extinguished one by one, and the consumption and illuminating power remained constant.
“The saving in gas by the application of the ‘Shaw’ governor was therefore 17·16 per cent., whilst the illuminating power of the gas was increased 11·31 per cent.
“These results need no comment, as they speak for themselves.