Observations upon Wheel- Carriage Experiments. 249 



found myself still on the surface and quite at my ease, with sIk 

 pounds avoirdupois in all. I had myself weighed immediately, 

 and foinid I weighed ISOlbs. avoirdupois. 



T!ie knowledge of this fact may perhaps give confidence to 

 some of your readers, who may be thrown into that situation 

 where confidence alone will preserve life. 



Should you deem this expertment worth recording, you will 

 oblige me by giving it a place in your Magazine. 

 I am, dear sir, 



Your obedient servant, 

 Surrey Institution, Sept. 14, 1815. KniGHT SpENCER. 



%* Will thank our correspondent if he will have the good- 

 ness to inform us, in a brief note for our next Number, whether 

 the flint stones were held under or above the surface of the 

 water. 



XLVII. Observations vpon IVheel- Carriage Experiments, svb- 

 mitled to the Comideration of the Dublin Society'^. By 

 TowM,Ey Richardson, Esq. 



Experiments, ^c. 



Exp. I. v^oMMON car against a Scotch dray, 



Exp. II. To determine whether the application of springs is 

 advantageous to the draught of carriages. 



Two carriages exactly similar, and both of them upon springs, 

 will be tried against each other, one having the springs pre- 

 vented from acting — the other having the springs at libertv. 



Exp. III. That carriage, which appeared to have the advan- 

 tage in Experiment the 2d, will be loaded till it nearly keeps pace 

 with the other carriage. — The difference of weigiit thus carrfed 

 will show the relative advantage of each carriage. 



Exp. IV. The 3d Experiment will be repeated, changing 

 the situation of the carriages, so that the different draughts of the 

 carriages may not appear to have been occasioned by the diffe- 

 rent roughness or smoothness of the track on which they ran. 



Exp. V. The relative advantages of short and long perches 

 will be compared, — Tv/o carriage*, similar in all respects, will 

 be compared ; and afterwards tiie same carriages, but with the 

 perch of one of them lengthened, will be compared. 



Exp. VI. The relative advantages of high and low carriages 

 will be compared. 



Exp, VU. Two one-horse drays, similar in all respects, ex- 



• Printed bj Order of the Dublin Society. 



ccpting 



