INDEX. 22 



p. 260 — his and Dr. Jones's account of lioufes in Phila. ftruck by 

 lightning. Vol. III. p. 119 — his and Mr. Hopkinfon's obfevvations on 

 tlie efFcifts of lightning on a houle with two conduiflors, 122 — his altro- 

 nomical obfervations, 150 — on the metliod of finding the fum of the 

 powers of tlie fines, &c. 155 — his account of a comet, 261 — his mrde 

 to determine the true place of a planet, in an elliptical orbit direftly 

 from the mean anomaly, by converging feries. Vol. IV. p. 21 — ^his 

 improvement of time-keepers, ib. p. 26 — his account of the expanficn 

 of wood by heat, ib. p. 29 — his method of raifmg the common loga- 

 rithm of any rumber immediately, ib. p. 69. 



River-nav'igiilhii, improvement in its boats. Vol. IV. p. 298 — inclined planes 

 preferable to locks, 299 — defcription of a boat recommended to be tiled, 

 301. 



Robi/ijon (Ebenezer) his eafy and expeditious method of difllpating noxious 

 vapours in wells, &c. Vol. III. p. 324. 



Rock, a curious one. Vol. II. p. 50. 



Rocks artificially and curioully marked, Vol. III. p. 219 — Vol. IV. p. 



, &c. (the ftrataof) beyond the mountains placed /jo/-;3cr/(7//y, Vol. IV. 



p. 227. 



Romr.n (ancient) fubllltute for efpaliers. Vol. I. p. I 70— how they preferved 

 vnne, 188. 



Romans (Bernard) on the mariner's compafs. Vol. It. p. 396. 



Rome, proportion of deatlis in. Vol. Ill p. 41, 59. 



Rooms, an improved mode of warming them, Vol. II. p. 29, 33. 



Rules of the A. P. S. two fundamental ones. Vol. I. p. iii. 



Rumfey's improvement on Barker's mill, obfervations on. Vol. III. p. 144. 



Rural economy, enquiries into, and how applicable to the U. States, Vol. III. 

 p. vii. 



Rujh (Dr. Benj.) on the caufe of the encreafe of bilious and intermitting 

 fevers in Pennfylvania ; with hints ior preventing them. Vol. II. p. 

 206 — on the late Dr. Martin's cancer-powder ; with obfervations on 

 cancers, 2 12 — on tlie caufe and cure of the tetanus, 225 — on the fugar- 

 maple, and manner of obtaining the fugar. Vol. III. p. 64 — his obfer- 

 vations Intended to favour a fuppofition, that the black colour (as itis 

 called) of the Negroes is derived from die leprofy, Vol. IV. p. 289. 



Ruji, the true original fea bifcuit. Vol. II p. 322. 



RuJJia and Sweden combine to raife the price of naval ftores, Vol. I. pref. 

 p. xiv. 



RuJJiarii unfuccefsful in obferving the tranfit of Venus in 1769, Vol. I. ap- 

 pend'ix. p. 3. 



Rujlon (Dr. Thomas) on the caufe, cure and prevention of fmoky chimnies, 

 Vol. II. p. 231. 



Saint Andre-xa, W. Florida (bay of) defcribed, Vol. I. p. 253. 

 Saint Auguftine, a nioft healthy climate, Vol. III. p. 49. 



Salem 



