[ I02S J 
I art of a tetter from Sr. R. B, to Dr. concern^ 
ingantw fort of Calefti. 
Sr. William Petty, Mr. Molyneux and I have fpent: 
this day in making experiments, with a new invent- 
ed' f^/^y??, along with the Inventor thereof 5 'tis he thar 
was in London when I was there, but he never made- 
any of thefe Calejhes there, for his invention is much im- 
proved fincehe came thence^ it is in all points different 
from any machine I have ever feen : It goes on two 
wheels-, carries one Perfon,- is light enough: a's for'its 
performance, tho' it hangs not on Braces, yet it is eafiier 
then the Common Coach, both in the high Avay, in 
ploughed Fields, crofs the ridges, dirccSlly, and oblique-- 
ly; a common Coach will overturn, if one wheel go oa 
afuperficies afoot andahalf higher then that of the o 
ther, but this wili admit of the difference ot 3\ foot in 
height of the fuperficies, without danger of overturning ; 
we chofe-airthe^irregular Banks, and fides of Drtches to 
run over, and I have this day feen it at five feverall times 
turn over and over, that is, th« wheels fo over- turnd as 
that their Spokes iye parallel to the Horizon, fo that one 
wheel fies flkt over the head of him that rides in the Ca- 
lejb, and the other wheel flat under him, but fo much 
I call but once overturnd. But what I have mentioned 
was another turn more, fo that the wheels were again in 
Statu^uo, and the Horfenot in the leaft diford^red. If 
theJHorfe (hould be in the leaft unruly, with the help of 
one pin, youdifengage hkn^from-the without any 
Inconvenience. I my felf have been once overtarnd,and 
kaew it not till I lookt up, and faw^ the wheel flat ovct^ 
