Of Winds and Sounds.

Second is to the Difference between theJfond and ‘Third, as the Numbers 3, 4, 6./"us if the Lengths of Strings, be as these^Umbers, they will sound an OBave, 3 to** > a Fifth, 2 to 3 ; and a Fourth , .3 to 4.

Again: Harmonical Proportion, between^Ur Numbers is, when the Firji is to the

Fourth

The Sound excited in the Glass seems one entiree ct, whereas it is in reality an Aggregate or Assemblagea n indefinite Number of Sounds, each effected bysingle Vibration of the Glass ; but as the Timesy ’sie Vibrations are so quick and short, their IntervalsJ*' be imperceptible, and consequently the Distinction(i the particular Sounds, which will therefore be lost, andf e whole will appear but one entire Sound. After theManner a red hot Coal wbirl’d about makes the^Pearance of a fiery Circle, because the Coal succeeds^ ev ery particular Point of the Circle so quick, thatImpression is made upon the Retina before theL of the last is obliterated, and so the Coal appearsey ery Part of the Circle.

j- *2. The Tremors of the Glass are made extremely^ ,'ble by putting a little Water into the Glass; for thestations of the Glass will by Degrees give Motion totjjj Water, which Motion will continually be increased5 |j 11 be thrown up from the Surface in Form of a Mist^ ° Ve r the Glass, and to a considerable Height aboveVer y way. It is remarkable that the Motion of thet}j e a W is in Form of a Vortex , circulating round bymdes of the Glass, and raging with impetuous3Ve s like the Sea after a prodigious Tempest.ijjct.3* Or otherwise these Vibrations of the Glass areof ^ sensible by'adjusting a Screw very near the Riminj? e Glass ; then upon striking the Glass, it .will iiri-he heard to strike against the End of the’ w bich vvill Ihcw not only the Vibration of the$i r y but also that in vibrating, the Form is alter’d fromto elliptical.

S 2