[ ] 
there was one made by Mr. DaCoJla , of 4 Inches 
Diameter, which rofc to 1190 Yards. The laft 
Trial was made the latter End of April 1750, where 
28 Rockets were fired in all, made by different Per- 
lons, and of different Sizes, from 1 Inch and a half 
Diameter to 4 Inches the moft remarkable of cftch 
Size were as follows; one of 1 Inch and a half 
role to 7 43 Yards; one of 2 Inches to 659 ; one 
of 2 Inches and a half to 880 ; another of the fame 
Size, which rofe to 1071 ; one of 3 Inches to 12 5^4; 
one of 3 Inches and a half to 1109; and. one of 4 
Inches j which, after having rofe to near 700 Yards, 
turned, and fell very near the Ground before it 
went our. Thefe were all made by Mr. Da Cojla. 
Befides thefe, there was one of the Rockets of 24 
Inches in Diameter, which rofe to 784 Yards, and 
another made by Mr. Banks of the fame Size to 
833- 
As the making oflarge Rockets is not only very ex- 
penfive, but likewil'e more uncertain than thole of a 
Idler Size, fo from the laft Experiments it is evident, 
that Rockets from 2 Inches and a half to 3^ Inches 
Diameter, are fufiicient to anfwcr all the Purpofes 
they are intended for } and I doubt not may be 
made to rife to an Height, and to afford a Light 
capable of being feen to confiderably greater Di- 
ftances than thofe before-men tioifd. 
Before I conclude this Account, it may not be 
improper to take, notice, that, tho J the Heights of 
the Rockets are fet down to a fingle Yard, it is not 
pretended the Method made ufe of (tho’ fufiicient 
tor all the Purpoles of thefe Experiments) is capa- 
ble of’determining the. Heights to fo great an Ex- 
amine fs : 
