( 1^9 ) 
III. An Account of an Experiment^ touching the 
propagation of Sound^ P^P^^ Sono^ 
rous Body into the common Air^ in one Bire^ 
Bion ojily, By Mr, Fr. Hauksbee, F. R,S. 
S INCE by the former^ Experiment aftual Sound 
could not be tranfmitted thro' a Space void of 
Air 5 I was inclin’d to try whether that Sound, 
which (hould be propagated in a Receiver, having 
a Communication with the open Air at one fmalL 
Apperture only, but otherwife intirely furrounded by 
a Vacmm:^ Whether I fay, that Sound would be in- 
creas’d, or continu’d Sounding longer, at each Stroke 
that Ihould be given the Bell, than it would do, 
were not its Body encompafs’d by fuch a M^dinm, 
In Older thereto, the Bell was included as in the 
pre-mei>tion’d Experiment^ only? the upper part of 
its Receiver , was fcrew’d a Box with Collars of 
Leather 5 and on the Top of the outward Receiver, 
was laid a Brafs-Plate with a wet Leather between: 
In the middle of which Plate, was likewife fcrcw’d 
another Brafs Box with Collars; as before. Thefe Re- 
ceivers when plac’d on the Pump, had- their Boxes 
handing dircdly one over the other. Thro’ both of 
them in that Pofition, I paft a hollow Brafs Tube, 
which exactly fitted their Perforations.* thus the in- 
ward Receiver had a Communication with the out- 
ward Air , and the outward Receiver thereby was 
fecur’d from the Ingrcfs of the Circumambient Medi~ 
um. Now when the Air contain’d between the Re- 
I i i ceivers 
