Improvements in Clocks.
Year: 1899

page_text: Improvements in Clocks.
A communication to me from THEODOR LAUDA, of Leitmeritz, in the Empire of
Austria, School Director
I, EDMUND EDWARDS, of the Firm of Edwards and Co., Chartered Patent Agents
and Engineers, of 65 and 66, Chancery Lane, in the County of Middlesex, do
hereby declare the nature of this invention to be as follows:-
Great inconvenience has hitherto been experienced, both in practice and in
scientific pursuits, owing to the time in different places on the world's surface
differing by the intervals of longitude expressed in time.
Great efforts have already been made to remove the disturbing influence due
to this cause, but how far the matter is still from a satisfactory adjustment,
notwithstanding these efforts, may be very clearly seen by a glance at a time table
of European railways, which shows that the times of arrival and departure are
expressed in some European countries, in West-European time: in
others according to Central-European time; and in others again in
East-European time: in France by Paris time: Greece by Athens
time: Portugual by Lishon time: Russia by St. Petersburg time, and the like,
in addition to which the local time appertaining to each part of the world also
plays its appropriate part.
The cause of the disturbing influence in question is, in any case, to be sought for
in some imperfection of the clock employed for measuring time-although the
same must be considered one of the most ingenious of human inventions-and
particularly in the imperfection existing in the usual clocks in that they indicate
only the time of the particular place for which they are regulated.
The object of the present invention is to construct a timepiece which will
indicate the time for any selected places on the earth's surface simultaneously,
not by any alteration of the mechanism but solely by a modification of the hands
of the clock. Thus, if, at a particular instant of time, the hour hands of the
ordinary clocks set for the different places chosen, he combined-their various
positions in regard to the compound hour hand being maintained-and the same be
done with regard to the minute- and second-hands of these clocks in relation to the
compound minute- and second-hands of a single clock, it becomes evident that the
latter will now necessarily indicate the time for all the various places simul-
taneously, all that is necessary being that the hands applying to each of the places
he easily recognisable for the purpose of determining the angles formed by the
several hour, minute,- and second-hands.
The first condition is easily fulfilled by providing each hand with the corres-
ponding name of the place to which it refers; and the second condition is com-
plied with through the fact that in a 24-hour dial the central angles of the
individual hour, minute,- and second-hands (in compound hour, minute, and
second-hands) represent in relation to the differences in longitude between the
places in question, the 24- and 1440-fold value of these differences of longitude,

page_text: and in a 24-hour dial, the undivided angles of the individual hour hands express
the double of the differences of longitude of the places concerned, whilst the com-
pound minute and second hands on the 24- and 12-hour dials remain the same.
The best means of setting and measuring the time are afforded by uniform
movements, for which purpose a movement of this kind was sought for in nature
and found in the almost perfect uniform movement of rotation of the earth.
Ordinary clocks are mechanical appliances for measuring time, which, by the
movement of their hands, imitate the movement, each of a single meridian, of
the earth's rotation on its axis (with absolute or relative angular velocity for
astronomical or mean time), whilst the improved clock is intended to imitate this
movement with reference to each selected meridian of the earth simultaneously.
The tracks of the terrestrial meridians in the fixed plane of the celestial
equator, which plane represents the extension of the plane of the terrestrial
equator, exhibit during the axial rotation of the earth the same angular velocity
as the terrestrial meridians themselves-the centre of the earth being taken as
the centre of the plane.
Every radius, as the track of an accurately determined terrestrial meridian,
consequently requires for a complete rotation, the time of an astronomical day
corresponding with the time of a complete rotation of the earth on its axis.
If, therefore, the fixed dial plate of a clock showing astronomical time, with 24-
hour dial, represents the fixed plane of the celestial equator-the north pole being
assumed as at the back of the dial--then each radius moves in this fixed plane
as the track of the accurately determined terrestrial meridian, with the same
angular velocity as that of the earth in its axial rotation.
It is, therefore, 'obvious, in the first place, that the hour hand of such an astrono-
mical clock with a 24-hour dial, is the track of the terrestrial meridian it deter-
mines, and to which the clock is regulated, and that the movement of the hour
hand is identical with the movement of the corresponding terrestrial meridian.
whilst the minute- and second-Lands indicate the movement of this terrestrial
meridian or hour hand, or at least a 24- and 1440-fold multiple thereof. Hence, at
the same moment the hour hands of two astronomical clocks in two selected places-
e.g., Greenwich and Berlin-form an angle equal to the difference in longitude
between these two places, whilst the central angles of the minute and second hands
are equivalent to 24 and 1440 times the difference in longitude between them,
whereby, of course, complete revolutions--as indicated in the first case by the hour
hand, and in the second by the minute- and second hands-may here he left out
of consideration.
If at this particular instant the two hour hands of both clocks in their definite
positions be united to form the compound hour hand of one single clock-their
common angular velocity being retained-and if in the same manner the two
minute- and second-hands be united to form the compound minute- and second-
hands, a clock is obtained which will indicate simultaneously the time at Green-
wich and Berlin, with as much accuracy as the mechanism of the clock permits.
That the foregoing argument dealing with two places can also be extended to all
places on the earth's surface, is very evident, and consequently the following
result appears:
That for all places on the earth, a single, perfectly accurate compound hour hand
can be formed, together with compound minute- and second-hands, appertaining to
an astronomical clock with 24-hour dial, which will indicate the time for
all places on earth simultaneously, just as ordinary clocks indicate the time for a
single place, the compound hour, minute, and second hands representing the com-
bination of the paths of the meridians in the plane of the equator, with once, 24
times, and 1440 times their mutual central angles, or the union of the simple hour,-
minute, and second hands for all places on the earth.
According to the actual purpose the clock is designed to serve, a definite group
of localities or places corresponding to this purpose may be selected, and it is
evident that, where the differences in time are small, a simple hour hand in the

page_text: compound hour hand can serve for a whole group of simple minute-and-second-
hands in the compound minute- and second-hands.
Thus, the astronomical clock can be at once converted into a 24-hour dial clock
recording mean solar time, by imparting to the compound hour, minute,-
and-second hands an angular velocity of 360° = 1 day mean time;
= 1 minute mean
time respec-
نال ازان
360° = 1 hour mean time; and
tively, everything else being left unchanged.
with a. 12-hour dial the compound hour hand is recognized as the union of the
paths of the terrestrial meridians in the plane of the equator after the doubling of
their mutual central angle, or the union of the simple nour hands for all places on
the earth. Moreover, such a clock can indicate the time of day at each place, if the.
movement of the hollow hour-hand spindle be transmitted to or geared with an axis
projecting through the dial-plate, and moving at one half the angular velocity, vaz.
360° 24 hours, the hand of which. moves over a small accessory dial-plate
inscribed with Morning,' "Forenoon," Afternoon," and "Evening."
A clock constructed on the basis of the foregoing details and designed for a
tour round the world, with particular regard to the following places:-Green-
wich, Liverpool, New York, Chicago, Ogden, San Francisco, Tokio, Shanghai,
Singapore, Calcutta, Aden, Malta, Lisbon and Greenwich, will indicate with
extraordinary precision, the time at all the places shown on the compound hands.
The time in other places:-Vienna, l'aris, Berlin, Madrid, Cadiz, Rome-given
upon the compound minute- and second-hands is indicated-so far as the hour is
concerned--by the position of the appropriate pointer (or hand) of the compound
hour hand for Malta, Greenwich, Lisbon, etc.
The shaft of the hour, minute,- and second-hands carries, in place of the simple
hand of an ordinary clock, the compound hand which is made up of the hands for
all the different places on the earth. Some of the simple hands are employed with
an attachment to the corresponding shaft, and also at the same time to serve as
carriers of the remainder, the outer ends of which are cut out in the form of a
ring, in order to allow the inner part of the dial and the figures on the dial plate
to be seen.
The three continuous circular rings constitute the incorporation of the three com-
pound hands, (the smallest being the hour hand, the middle one the minute hand,
and the largest the second hand), as a combination of the hands of all the places
on the earth, and, as in ordinary clocks, move in graduated circles for the
purpose of recording the hours, minutes, and seconds, the hand for any particular
place being shown by having the name of that place inscribed upon it.
The central angles of the simple hour, minute,- and second-hands of individual
places, in the compound hands, are equivalent, in 24-hour dials, to once,-24
times, and 1440 times, the difference in longitude between the places, but in
12-hour dials they are equivalent to,-twice-24 times, and 1440 times, the
differences of longitude.
In the 12-hour dial the time of day is told by the hands for (say) Greenwich,
Chicago, and Calcutta, moving over the small accessory dial bearing four divi-
sions of day-time..
(6°
=
(15°
=
=
.
As an example, Tokio, with a difference of longitude of +9 hours 18 minutes
58 seconds from Greenwich, may serve. The central angle in time, made by the
Greenwich-Tokio hands on a 24-hour dial is, in the compound second hand,
+58 sec., or
_ 2 sec., (60 1 sec), in the compound minute hand, + 18 min. 58 sec.
1 min.), and in the compound hour hand +9hrs. 18 min. 58 sec.
1 hr.); in a 12-hour dial the same as before, for the second- and minute
hands, while in the hour hand it is + 9 hrs. 18 min. 58 sec.. (30°
When the clock marks for Greenwich the hour of 7 hrs. 20 min. 15 sec. post meri-
diem, the Tokio hand indicates the hour as 4 hrs. 39 min. 12 sec. ante meridiem,
whilst the hand for indicating Calcutta time points to (1 hr. 13 min. 36 sec.)
ante meridiem.
=
1 hr.).
As regards the utility of the improved clock, it may suffice to remark how it facili»

page_text: tates the simultaneous observation of phenomena for any desired meridians; or
how, by means of a model, the observations taken at different places can be accur-
ately reduced to uniformity of time without any calculation; how easy it becomes
to determine the meridian of any selected place at actual noon; that the adjustment
of clock for different meridians becomes unnecessary; that the time tables of
the entire world can be brought into complete harmony, since. they can be drawn
up according to local time because the railway clocks also indicate the time accord-
ding to the local meridian as is requisite for local purposes; that in starting on a
long journey the clock can be arranged so as to indicate the principal stations,
while for shorter journeys the use of the compound minute hand in conjunction
with one or more of the simple hour hands will be sufficient.
Dotad 10
W 1000
A communication to me from THEODOR LAUDA, of Leitmeritz, in the Empire of
Austria, School Director.
1, EDMUND EDWARDS, of the Firm of Edwards and Co., Chartered Patent Agents
and Engineers, of 65 and 66, Chancery Lane, in the County of Middlesex, 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, and accompanying drawings, that is to say:-
This invention has for its object to provide a clock which simultaneously
indicates the right time of various Jaces on the earth-the day time being shown in
subdivisions of a dial-with the same accuracy as thai at present obtained, and in
the same manner as has hitherto been done with clocks having ordinary bands.
The novelty of the invention consists in making use, instead of ordinary
simple hands, of circular shaped indicators (or hands) which being provided with
radially drawn lines and the names of various places of the earth, may be taken
as the orthogonal equatorial projection of different meridians of the earth, and
which are combined with dials suitably divided in subdivisions.
On the accompanying drawing, which is in illustration of this invention, Figure 1
shows a front view of such a clock, and Figure 2 a cross section of the same.
In Figure 3 one of the indicators (hands) with its dial is represented on an
enlarged scale.
,
The illustrated specimen is based on the fact that all the dials are stationary,
and that the indicators (or hands) are made to revolve.
The dial-plate of the clock, having at its front four projecting spindles for the
indicators, is marked A. On these spindles are mounted the circular-shaped
indicators or hands C, D, E, and F, the spindle of C exactly completing one whole
revolution during the course of a day, that of 1 completing two such revolutions,
that of E twenty-four, and that of F 1440 revolutions in the same space of time.
Each indicator, C, D, E, F, is provided with lines drawn in the radial direction
and with the names of the selected places of the earth, that is to say, each of these
indicators indicates the series of marks with reference to the orthogonal equatorial
projection of the net of meridians of the globe-in its true extent, or double

page_text: this extent, or 24 times, or 1440 times respectively, as great as the central angle
of the meridian in question. By this means it is rendered possible to read upon
all the indicators the exact position of the meridians drawn through the selected
places for which the clock is to give the right time, in the same manner as has
hitherto been done with clocks having ordinary simple hands, these latter, how-
ever, simultaneously showing the right time on the circular shaped indicators.
The hand which is firmly mounted upon the spindle B indicates the.
marks ; e, ell, of the meridians drawn through Greenwich, Chicago and Calcutta.
respectively, and the dial combined with this hand shows the day times, whilst
the hands, D, E, and F, indicate the marks of the meridians of a further number
of selected places of the earth, and revolve opposite to subdivisions of the dial, upon,
which 360° are supposed to be equal to half a day (12 hours), or to one hour, or.
to one minute respectively, that is to say, the divisions running in the direction
of the revolutions successively indicate, by means of their subdivisions, the hours
of half a day, the minutes of an hour, and the seconds of a minute.
It is therefore rendered possible to read-for each of the selected places marked
on the circular-shaped indicators, D, E, F-upon the dial combined with the indica-
tor D the hour, upon that of E the minute, upon that of F the second, of the right
time of the meridians in question.
With reference to Figure 1, for example, it may be seen from the position of
the various indicators, that it is 7h. 20m. 15s. at Greenwich-7 being read from the
dial combined with the indicator D just opposite the subdivision
"
Greenwich"
drawn in a radial direction-20 being read from the dial combined with indicator E
opposite the sub-division line belonging to Greenwich-and 15 from the dial of.
indicator F opposite the subdivision line of the same place.
At the same time it may be seen that, simultaneously at Chicago it is:
1h. 29m. 323s., at Calcutta ih. 13m. 36s., and so on.
But as the dial combined with indicator D) is divided into 12 hours, it has not yet:
been possible to ascertain if the marks read from the dials relate to the first or to
the second half of the day.
This uncertainty is, however, easily removed by looking at the day time marked
opposite the lines drawn in a radial direction upon the indicator C; it may be at once.
observed that it is 7h. 20 m. 15s. p.m. at Greenwich, 1h. 29m.. 32s. p.m. at Chicago,
and 1h. 13m. 36s. a.m. at Calcutta.
All the places, however, for which the clock is to indicate the right time,
need not be named upon all the hands, for, as is well known, the difference in
time of two selected places, their geographical meridians being 15 degrees apart,
is equal to one hour, or in other words, a difference of degree of the respective
meridians is equal to one minute, that is to say, 34 degrees correspond with of
an hour it is therefore rendered possible to unite all the places which differ with
reference to their respective meridians from those marked on the dials only by
certain small central angles into one group upon the indicator or hand in question,
and to indicate upon the indicators or hands only places, the angle velocity of
which is greater than that of the indicator on which the common place of reference
(corresponding to them) is marked.
With reference to Figure 1, for example, the places "Rome," "Berlin," and
"Vienna," are not named upon the dial combined with the indicator D, the
meridians drawn through these places differing so little from the meridian drawn
through Malta" which is marked upon the indicator 1), that the right time at
"Rome," "Berlin," or Vienna respectively differs less than one quarter of
an hour.
"
Consequently, the time read upon the dial combined with the indicator ])
opposite the meridian-line of Malta" corresponds also with the right time at
Rome, Berlin, or Vienna, with an error of a quarter of an hour at the most;
5 the correction of the hour figure of the said places, if required, may be effected at
once by looking at the dials combined with the indicators E and F; in Figure 1
it is.

page_text: Sh. 13m. 50s. at
Berlin,"
Sh. 25m. 41s. at " Vienna."
Supposing, however, it is 8h. 5m. 19s. at " Malta, the position of the minute
hand for Kome" would point to 57, whilst that of the hour hand (for Malta) points
to S, that is to say, by making use of the ordinary simple hands, the observer would
read 3 minutes to 8 o'clock, of 7h. 57m.
Similarly, only some of the places need be named upon the dial combined with
the indicator C, for which places the clock is to indicate the right time, whilst the
other selected places may be united in groups when the difference of the meridian
drawn through one or the other places named upon C is, for example, 45° at the
most, that is to say, the difference of time between one or the other of these places.
only reaches three hours; thus, with reference to Figure 3, for example, the day
time of Greenwich is also available for "Liverpool,' Malta," Lisbon," erring
three hours at the most. This error is, however, easily corrected by looking at
the other indicators; the day time of Calcutta" is similarly available also for
Tokyo, Shanghai, Singapore; and the day time of "Chicago" also corresponds
with that of New York."
"
"
"
The place of reference to which those belonging to one and the same groups
of places relate, is also marked upon the various indicators, thus, for example, in
Figure 1 upon the hands or indicators E and I are marked the meridians drawn
through Rome," "Berlin," and Vienna," together with that drawn through
Malta"; by this means it is indicated that the hour-figure of the said places
must be read upon the dial combined with the indicator D. In the same manner
the indicators D, E, and F are marked with the lines of the meridians drawn
through Liverpool," "Malta," "Lisbon," c, with those drawn through Tokio,"
Shanghai," Singapore," and with that drawn through "New York," the
letter, by which means it is indicated that the day-time for the said places must
be read at the corresponding meridians, c, c, e upon the dial combined with the
indicator C.
Upon this indicator C, the meridians c, c¹, ell may be indicated by different
colours, for example by blue, red, and yellow; and upon the other indica-
tors, D, E, F, the meridians for which the day time is to be read at c are blue,
those for which the day time must be read at e¹ are red, and so on.
The meridians upon the indicator D which are drawn through places of reference,
relating to places upon the indicators E and F may receive a figure, which is
also found at the meridians drawn through the places last mentioned.
It is, of course, obvious, that the arrangement of the indicators and that
of the dials combined with them may be made in any other manner than those
indicated by the accompanying drawing. Thus, for example, the indicators may
be made stationary and the dials to revolve; the clock may be provided with a dial
divided into 24 parts (hours) instead of with a dial for 12 hours, as represented
in the drawing. According to the said division, the indicator I would then be
provided with the exact size of the central angles of the corresponding meridians,
instead of showing double that size as in the drawing.
The clock may also be constructed with the hour-indicator arranged excen-
trically.
Having now particularly described and ascertained the nature of the said in-
vention, and in what manner the same is to be performed, I declare that what
1 claim is:
A clock having an arrangement for simultaneously indicating the right time
of different places of the earth, the hands of such clock being combined with
suitable subdivided dials of circular shape, and provided with lines drawn in a
radial direction and with the names of places; the said lines being drawn at

page_text: distances apart from each other which correspond to angles represented in the
same relative proportion, with respect to their meridian centre angles, (or the
true size of the meridian centre angles of the orthogonal equatorial projection
of the net of meridians drawn through the places in question), as the daily
number of revolutions of the indicators stands to that of a hand or indicator com-
pleting only one single revolution in the course of a day, substantially as described
and illustrated.
EDWARDS AND CO.,
Chartered Patent Agents, 65 and 66, Chancery Lane, London,
Agents for the Applicant.