1and R. Hook (who hath alſo the Honor to
be known to your Lordſhip, and was with
me when I had theſe things under conſi
deration) to contrive ſome Air Pump,
that might not, like the other, need to
be kept under water (which on divers oc
caſions is inconvenient) & might be more
eaſily manag'd: And after an unſucceſsful
try all or two of ways propoſ'd by o
thers, the laſt nam'd Perſon fitted me
with a Pump, anon to be deſcrib'd. And
thus the firſt Imperfection of the German
Engine, was in good meaſure, though
not perfectly, remedy'd: And to ſupply
the ſecond deſect, it was conſidered that
it would not perhaps prove impoſſible to
leave in the Glaſs to be empty'd, a hole
large enough to put in a Mans Arm
cloath'd; and conſequently other Bodies,
not bigger then it, or longer then the in
ſide of the Veſſel. And this Deſign
ſeem'd the more hopefull, becauſe I re
membred, that having ſeveral years be
fore often made the Experiment De Va
cuo with my own hands; I had, to exa
mine ſome conjectures that occurr'd to
me about it, cauſed Glaſſes to be made
with a hole at that end, which uſes to be
ſeal'd up, and had nevertheleſs been able
be known to your Lordſhip, and was with
me when I had theſe things under conſi
deration) to contrive ſome Air Pump,
that might not, like the other, need to
be kept under water (which on divers oc
caſions is inconvenient) & might be more
eaſily manag'd: And after an unſucceſsful
try all or two of ways propoſ'd by o
thers, the laſt nam'd Perſon fitted me
with a Pump, anon to be deſcrib'd. And
thus the firſt Imperfection of the German
Engine, was in good meaſure, though
not perfectly, remedy'd: And to ſupply
the ſecond deſect, it was conſidered that
it would not perhaps prove impoſſible to
leave in the Glaſs to be empty'd, a hole
large enough to put in a Mans Arm
cloath'd; and conſequently other Bodies,
not bigger then it, or longer then the in
ſide of the Veſſel. And this Deſign
ſeem'd the more hopefull, becauſe I re
membred, that having ſeveral years be
fore often made the Experiment De Va
cuo with my own hands; I had, to exa
mine ſome conjectures that occurr'd to
me about it, cauſed Glaſſes to be made
with a hole at that end, which uſes to be
ſeal'd up, and had nevertheleſs been able