Transcriber’s Note: Chinese Tone Marks.
The printed text uses semi-circular tone marks next to some Chinese characters with multiple or ambiguous pronunciations (Unicode U+A700–U+A707). The open portion of the semi-circle faces the character. These were originally used to indicate tones used in Middle Chinese.
The mark may be placed in any of the four corners of the Chinese character. In modern Mandarin Chinese the locations map to tones as follows:
lower left: 1st or 2nd tone
upper left: 3rd tone (some cases 4th tone)
upper right: 4th tone
lower right: not applicable for modern Mandarin
Examples from the text:
重 zhòng (adj) heavy, important
꜀重 chóng (adv) repeatedly; (measure) layer, storey
語 yǔ (n) spoken language
語꜄ yù (v) to tell, inform
For more details on tone marks, look up articles on ‘Middle Chinese tones’ or see：
Williams, S. Wells. 1874. A Syllabic Dictionary of the Chinese Language; arranged according to the Wu-fang Yuen yin, with the pronunciation of the characters as heard in Peking, Canton, Amay and Shanghai. Shanghai: American Presbyterian Mission Press.
Introduction SECT. IV.—SHING OR TONES.