Helderberg  Hills,  or  Mountains,  N.  Y.,  stretch
through  the  W.  part  of  Albany  co.,  into  Scho-
harie  co.,  where  they  unite  with  the  Catskill
range.  They  consist  of  a  series  of  limestones  of
varied  mineralogical  character,  upon  a  foundation
of  graywacke.  and  abound  in  fossil  remains,
and  extensive  caverns  ornamented  with  stalac
tites  and  stalagmites.  These  mountains  are  very
precipitous,  and  are  from  400  to  500  feet  in
height.
Hell  Gate,  or  Hurl  Gate,  a  strait  in  the  East
River,  8  miles  from  New  York  city,  between  the
Islands  of  Manhattan  and  Parsell,  on  the  N.  W.,
and  Long  Island,  on  the  S.  E.  It  is  said  that  the
proper  name  of  this  strait  is  Horll  Gatt,  a  Dutch
term,  signifying  a  whirlpool.  Through  this  nar
row  pass  the  tides  flow  in  and  out,  between  the
harbor  of  New  York  and  Long  Island  Sound.
At  certain  stages  of  the  tide,  the  waters  rush
through  here  with  a  powerful  current,  and  pass
ing  over  sunken  rocks,  are  made  to  whirl  and
roar  with  fearful  violence.  There  is  no  great
difficulty,  however,  in  navigating  the  strait  with
safety,  under  the  guidance  of  a  skilful  pilot.
Ifell  Gate,  On.  An  E.  branch  of  Bitter  Root
River,  rising  among  the  Rocky  Mts.
Helley'a  Keys,  Fa.  These  islands  separate  Taga-
bona  Bay  from  the  Gulf  of  Mexico.
Hemlock  Island,  St.  Lawrence  co.,  N.  Y.,  lies  in
the  St.  Lawrence  River,  and  is  attached  to  the
town  of  Clayton.
Hemlock  Lake.  N.  Y.,  lies  partly  in  Livingston,
and  partly  in  Ontario  co.  It  is  6*miles  long,  aud
1  mile  wide,  discharging  its  waters  into  the  outlet
of  Honeoye  Lake.
