Ellen: Or, Whisperings of an Old Pine, Volume 2

altitude angles formed apothems base and altitude called cause centre chords circle circumference condensation cone convex surface COROLLARY cosine curved cylinder demonstration density diameter dimensions direction distance elastic force Ellen thinks equal angles ether exist figure fluid frustum given half the difference half the sum heat Hence hypotenuse increased inscribed angle intersection lateral edges length logarithms mathematics matter medium minus molecules motion move movement nature Newton odorous odorous bodies old Pine parallel planes parallelopiped particles perpendicular plane angles polygon possible principles prism propagated proportional PROPOSITION pulses pyramid quantity radii radius ratio rectangles represents right angles scientists secant sensation side opposite similar sine a+b slant height smell space sphere spherical angle spherical excess spherical triangle square straight line substance subtended supposed tang tangent of half thing tion Trigonometry Tyndall undulatory theory uniform divergence velocity of sound vertex vibration volume waves Yale College