An Instrument for Demonstrating Astronomical Phenomena.
Year: 1889

page_text: Date of Application, 31st Oct., 1889
Complete Specification Left, 11th July, 1890-Accepted, 4th Oct., 1890
PROVISIONAL SPECIFICATION.
An Instrument for Demonstrating Astronomical Phenomena.
I, JOHN GEORGE l'ARVIN, of 12 Duncombe Road, Hornsey Rise, in the County of
London, Mercantile Clerk, do hereby declare the nature of my said invention for
"AN INSTRUMENT FOR DEMONSTRATING ASTRONOMICAL PHENOMINA to be as
follows:-
:-
My invention is intended to be used for indicating the position in the heavens of
any planet, and of the moon, and fixed stars, at what hour the same will rise, pass
the meridian, and set. It will also indicate the phases of the moon and when lunar
eclipses will take place..
I provide a disc on which are drawn a séries of concentric circles divided and
inscribed appropriately.
Upon the said disc and attached thereto by guides working on its edge or other-
wise attached so that it may be made to revolve concentrically with the first disc is
a second and smaller disc on the outer edge of which is a circle divided into twenty
four hours and subdivisions, and in the central part of which, within the said circle,
but not concentric therewith, is an opening of such size and shape as to represent the
horizon of the place in which the apparatus is intended to be used, say for instance,
London. This disc is capable of being rotated on the first or larger disc so that the
two may be made to assume or pass through any desired relative radial positions, so
as to show through the said opening the fixed stars drawn on the first disc visible at
any given time, and I prefer to cut away so much of the smaller disc as is not required
for the hour circle and to represent the horizon leaving only narrow bands between
to support these and thus avoid unnecessarily covering up and hiding the portions of
the larger disc.
At the centre of the first dise I attach one two or more indexes or pointers so
arranged that it or they or either of them may be set to any required point or points
and preferably so arranged at the centre that they may be moved a limited distance in
the direction of their length and on the said pointer or pointers I attach, to each, a
small knob or indicator that may be moved either with or indepently of the pointer
towards or from the centre and set at any required distance, I generally use two
pointers and make one of them "Earth" and the other one "Planet" and I inscribe
a scale on the said pointers representing declination.
On the first named that is to say the larger disc is inscribed a series of circles
divided and marked as follows but the order of the circles need not be that
stated below as it may be varied considerably without departing from my invention.
The outer circle of the said disc I divide and number to represent right ascension,
the next inwards may be marked with the corresponding signs of the zodiac then.
inay come an anular space over which the hour circle forming part of the second
disc lies; further inwards inay be a circle or circles representing the division of the
year into months and their sub-divisions into days. On the space within these
circles I represent some of the principal fixed stars, or so many of them as are
within the zodiac.
If preferred the right ascension circle may be placed nearer the centre and
within the lines representing the zodiac among the fixed stars.
By setting the pointer marked "Earth" to the day of the month and the pointer
tarked "Planet" to the right ascension of any planet, and setting the indicator
on the planet pointer to the planet's declination, and then moving the apparatus so
that the indicator on the planet hand is brought over the eastern portion of the
horizon, the time of the rising of the planet is indicated by the pointer on the hour

page_text: Date of Application, 31st Oct., 1859
Complete Specification Left, 11th July, 1890-Accepted, 4th Oct., 1890
PROVISIONAL SPECIFICATION.
An Instrument for Demonstrating Astronomical Phenomena.
I, JOHN GEORGE PARVIN, of 12 Duncombe Road, Hornsey Rise, in the County of
London, Mercantile Clerk, do hereby declare the nature of my said invention for
"AN INSTRUMENT FOR DEMONSTRATING ASTRONOMICAL PHENOMINA
to be as
follows:-
:-
"
My invention is intended to be used for indicating the position in the heavens of
any planet, and of the moon, and fixed stars, at what hour the same will rise, pass
the meridian, and set. It will also indicate the phases of the moon and when lunar
eclipses will take place..
I provide a disc on which are drawn a series of concentric circles divided and
inscribed appropriately.
Upon the said disc and attached thereto by guides working on its edge or other-
wise attached so that it may be made to revolve concentrically with the first disc is
a second and smaller disc on the outer edge of which is a circle divided into twenty
four hours and subdivisions, and in the central part of which, within the said circle,
but not concentric therewith, is an opening of such size and shape as to represent the
horizon of the place in which the apparatus is intended to be used, say for instance,
London. This disc is capable of being rotated on the first or larger disc so that the
two may be made to assume or pass through any desired relative radial positions, so
as to show through the said opening the fixed stars drawn on the first disc visible at
any given time, and I prefer to cut away so much of the smaller disc as is not required
for the hour circle and to represent the horizon leaving only narrow bands between
to support these and thus avoid unnecessarily covering up and hiding the portions of
the larger disc.
At the centre of the first disc 1 attach one two or more indexes or pointers so
arranged that it or they or either of them may be set to any required point or points
and preferably so arranged at the centre that they may be moved a limited distance in
the direction of their length and on the said pointer or pointers I attach, to each, a
small knob or indicator that may be moved either with or indepently of the pointer
towards or from the centre and set at any required distance, 1 generally use two
pointers and make' one of them "Earth" and the other one "Planet" and I inscribe
a scale on the said pointers representing declination.
On the first named that is to say the larger disc is inscribed a series of circles
divided and marked as follows but the order of the circles need not be that
stated below as it may be varied considerably without departing from my invention.
The outer circle of the said dise I divide and number to represent right ascension,
the next inwards may be marked with the corresponding signs of the zodiac then
inay come an anular space over which the hour circle forming part of the second
disc lies; further inwards may be a circle or circles representing the division of the
year into months and their sub-divisions into days. On the space within these
circles I represent some of the principal fixed stars, or so many of them as are
within the zodiac.
If preferred the right ascension circle may be placed nearer the centre and
within the lines representing the zodiac among the fixed stars.
By setting the pointer marked "Earth" to the day of the month and the pointer
marked "Planet" to the right ascension of any planet, and setting the indicator
on the planet pointer to the planet's declination, and then moving the apparatus so
that the indicator on the planet hand is brought over the eastern portion of the
horizon, the time of the rising of the planet is indicated by the pointer on the hour

page_text: circle, and in the same way the time of its meridian passage and its setting may be
obtained and its position among the fixed stars.
The apparatus will by various operations of a similar kind give the like indications
respecting the moon, its phases and eclipses, and much other useful information.
Dated the 31st day of October 1889
NEWNHAM BROWNE,
Agent for the Applicant.
COMPLETE SPECIFICATION.
An Instrument for Demonstrating Astronomical Phenomena.
JOHN GEORGE PARVIN 12 Duncombe Road Hornsey Rise in the County of London
Mercantile Clerk, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by the
following statement :-
My invention is intended to be used for indicating the position in the heavens of
any planet and of the moon and fixed stars, at what hour the same will rise, pass the
meridian and set, it will also indicate the phases of the moon and when the lunar
eclipses will take place.
I provide a disc on which are drawn a series of concentric circles, divided and,
inscribed appropriately. Upon the said disc and attached thereto by guides working
on its edge or otherwise attached so that it may be made to revolve concentrically,
with the first disc is a second and smaller disc on the outer edge of which is a circle
divided into twenty-four hours and sub-divisions, and in the central part of which,
within the said circle, but not concetric therewith, is an opening of such size and
shape as to represent the horizon of the place in which the apparatus is intended to be
used, say for instance London.
This disc is capable of being rotated on the first or larger disc, so that the two may
be made to assume or pass through any desired relative radial positions, so as to show
through the said opening the fixed stars drawn on the first disc visible at any given
time, and I prefer to cut away so much of the smaller disc as is not required for the
hour circle and to represent the horizon, leaving only narrow bands between to
support these and thus avoid unnecessarily covering up and hiding the portions of the
larger disc.
At the centre of the first disc. I attach one two or more indexes or pointers so
arranged that it or they or either of them may be set to any required point or points
and preferably so arranged at the centre that they may be moved a limited distance in.
the direction of their length, and on the said pointer or pointers, I attach to each, a
small knob or indicator that may be moved either with or independently of the pointer
towards or from the centre and set at any required distance. I generally use two
pointers, and mark one of them "Earth" and the other one Planet" and 1
inscribe a scale on the said pointers representing declination.
On the first named, that is to say the larger disc is inscribed a series of circles
divided and marked as follows, but the order of the circles need not be that stated
below as it may be varied considerably without departing from my invention.
The outer circle of the said disc I divide and number to represent right ascension,
the next inwards may be marked with the corresponding signs of the zodiac, then may.
come an annular space over which the hour circle forming part of the second disc lies,
further inwards may be a circle or circles representing the division of the year into
months and their sub-divisions into days. On the space within these circles I
represent some of the principal fixed stars or so many of them as are within the
zodiac. If preferred the right ascension circle may be placed nearer the centre and
within the lines representing the zodiac among the fixed stars.
29
By setting the pointer marked "Earth to the day of the month, and the pointer
marked Planet to the right ascension of any planet, and setting the indicator on
the planet pointer to the planets declination, and then moving the apparatus so that

page_text: the indicator ou the planet hand is brought over the eastern portion of the horizon, the
time of the rising of the planet is indicated by the pointer on the hour circle, and in
the same way the time of its meridian passage and its setting may be obtained and its
position among the fixed stars. The apparatus will by various operations of a similar
kind, give the like indications, respecting the moon, its phases and eclipses and much
other useful information.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. To indicate the position in the heavens of any planet & fixed star.
2. To show at what hour the aforesaid will rise, pass the meridian and set.
A
Dated the 11th day of July 1890.
JOHN GEORGE PARVIN.