[48^3 
And thefe Otacoujhcks in fome refpecfls would be of 
gtt2LtQT uk then Per fpeSlives. For whereas at land P^r- 
JpeSlives^xQ many times render d almoft ufelefs, by the 
interpofitionof Woods and Mountains, which hinder the 
Sight from reaching very far : our OtacoujHcks would, 
notwithftanding thefe Obftacles, take in a Sound made 
fome leagues off. Which might be of notable ufe in the 
time of War, for difcovering the Enemy at agooddi- 
ftance, when he marches or lyes incamp'd behind a 
Mountain or Wood, or any fuch place of flielter. 
Yea even at Sea alfo, where PerfpeBives are of moft 
ufe, by reafon of the plainels of the furface of the Wa- 
ter ; Yet fometimes there Otacoujiicks may be of more 
benefit, when in dark, hazy weather the air is too thick, 
or in Stormy Tempeftuous weather the Waves rife too 
high, for the PerfpeUive to be made ufe of 
But whether at or La7id, Perfpt^iv s become alto- 
gether infignificant in the night time ( unlefs it be for 
viewing the Stars j which is the chief time for ufing 0- 
tacoujiicks ; as it is generally, for Souldiers to take their 
march, when they would furprife their Enemies. 
And therefore this fort of Otacoujiicks have then their 
chief ufe, when PerfpeBives zxq of no ufe at all; befides 
that they maybe imploy'd in the day time, as well as 
Perfpcilives; whence they may ( not unfitly ) be termed 
the moft ufeful Injirument of the two. 
K^Micr of copes or Magnifying Glajfes, help the Eye 
to feenear Obje^s, that by reafon of their fmalnefs were 
Invifible before : which Objects they Magnify to a ftrange 
greatnefs : So Microphones or Micracoujiichs , that is. 
Magnifying Ear Inftruments may be contriv'd after that 
manner, that they flia 11 render the moft minute Sound in 
nature diftindtly Judible, by Magnifying it to an uncon- 
ceivable loudneis. 
By the help hereof we may hear the different cries and 
tones, as well as by Microscopes fee the divers Shapes and 
Fi- 
