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CONTENTS 



VOLUME IV. 



N". Page, 



I. JlL XPERIMENTS and olfervations rclafhig to the Analyfis of At- 



niofpherkal air, by the Rev. Dr. J. Prieftley, r 



II. Farther Experiments relating to the Generation of Air from Water, by 

 Rev. Dr J. Prieftley, 1 1 



KI. To determine the true Place of a Planet, in an Elliptical Orbit, direHly 

 front the mean Anomaly, by Converging Series, by David Rittenhoufe, 

 L. L. D. Prejident A. P. S. 21 



IV. On the Improvement of Time-keepers, by David Rittenhoufe, L. L. D. 

 Preftdcnt of the Society, 26 



V. On the Expanfion of Wood by Heat, in a Letter from David Ritten- 

 houfe, L. L. D. Prefident of the Society, 29 



VI. A Letter from Mr. Andrew Ellicott, to Robert Patterfon ; in Tnuo 

 Parts, 3 2 



VII. Of the Aberration of the Stars, Nutation of the Earth's Axis, and 

 Semi-annual Equation, by Andrew Ellicott, 51 



VIII. A Letter from Mr. Andrew Ellicott, to Mr. Robert Patterfon. 



A Method of Calculating the Eccentric Anomaly of the Planets, 67 

 rX. Method of raiflng the common Logarithm of any Number immediately, 



by David Rittenhoufe, Prfident of the Society, 69 



X. Experiments on Evaporation, by C. Wiftar, M. D. 72 



XI. A Memoir concerning the Fafcinating Faculty which has been afcribed 

 to the Rattle-Snake, and other American Serpents. By Benjamin Smith 

 Barton, M. D. 74 



XII. Some account of an American Species of Dipus, or Jerboa. By 

 Benjamin Smith Barton, M. D. 114. 



XIII. A Letter from Mr. John Heckewelder, to Dr. Barton, giving 

 fome account of the remarkable inflind of_ a bird called the Nine- Killer, 1 24 



XIV. An Enquiry into the caufes of the Infalubrity of flat and Marfljy 

 Situations ; and direBions for preventing or correcting the EJfeds thereof, 



by William Currie, 127 



XV. Defcriplion of a Machine for faving Perfons from the upper Stories of 

 a Houfe on fire, by Nicholas Collin, D. D. the Inventor i with a 

 Drawing from the Model, 143 



f XVI. A 



