Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. While inventors were busy bringing out new types of governors, usually without any knowledge of the mutual relations between prime mover and governor, these very rela tions were studied by two widely different types of men, namely the operating engineer, and the mathematician. The former found that the wonderful isochronous governors, such as the parabolic governor, the cosine governor, and many others, were worthless because they caused perpetual hunting and racing. Oil gag-pots were found to be necessary; and fre quently stabilizing springs were concealed in them; but with all this practical progress, the theoretical foundation or proof for the exasperating behavior remained unknown to engineers, or else was not understood by them.

While inventors were busy bringing out new types of governors, usually without any knowledge of the mutual relations between prime mover and governor, these very rela tions were studied by two widely different types of men, namely the operating engineer, and the mathematician. The former found that the wonderful isochronous governors, such as the parabolic governor, the cosine governor, and many others, were worthless because they caused perpetual hunting and racing. Oil gag-pots were found to be necessary; and fre quently stabilizing springs were concealed in them; but with all this practical progress, the theoretical foundation or proof for the exasperating behavior remained unknown to engineers, or else was not understood by them.