Improvements in Electro-motors and Dynamo-electric Machines.
Year: 1887

page_text: Improvements in Electro-motors and Dynamo-electric Machines.
J, WILLIAM MAIN, of number 857 Marcy Avenue, in the City of Brooklyn, in the
County of Kings in the State of New York, United States of America, Electrical
Engineer, 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 :-
This invention relates chiefly to electro-motors, but it is also applicable to dynamo-
electric or magneto-electric generators. Its objects are to combine the utmost
efficiency with the least weight and the greatest compactness that are practically
possible in such machines.
In an electro-motor or dynamo the magnetic circuit consists of two parts, one
comprised in the field magnet and the other'in the armature. Throughout this circuit
tbere exists, during excitation, a condition of strain known as magnetism which
develops itself along certain lines known as lines of force. In a closed magnetic
circuit these lines of force are confined entirely within the circuit; but in motors and
dynamos it is necessary for mechanical reasons to leave a gap or air-space at two
places in the magnetic circuit in order to divide the moving from the stationary part
thereof, and across these gaps the lines of force are compelled to stretch themselves
through air. If the armature were removed the lines of force would stretch them-
selves across between the terminals or pole-pieces of the field-magnet, the intervening
space being what is commonly known as the "field of force." It is desirable in a
motor or dynamo to make the resistance of the magnetic circuit as low as possible,
in order to avoid magnetic saturation and other sources of loss of magnetic energy.
The field-magnet should be given such shape that there shall be the least possible
short circuiting of the lines of force, in order that all the lines of force shall be
collected or concentrated in the "field of force."
The armature consists essentially of coils or convolutions of wire or other
conductor, being placed in the field of force and revolved therein in such manner
that each coil shall at times be traversed by lines of force passing through it,
which lines of force become more or less dense or numerous from time to time,
or which change their direction relatively to the coil. Thus an armature, such
for instance, as a Gramme ring armature, or other operating on a similar prin-
ciple, is simply a device for throwing coils of wire around the lines of force,
then removing them, again throwing them around, and again removing them, all

page_text: in one revolution or part of a revolution. By the reaction of the lines of force upon
the conductor electrical currents are induced in the latter in alternately opposite
directions, the alternating currents being ordinarily rectified by the commutator and
directed as a continuous current into an external circuit. Or, operating as a motor,
a continuous external current, being directed by the commutator into the armaturé
coils, reacts against the stationary lines of force and drives the coils forward,
thereby rotating the armature and converting electrical energy into mechanical
motion.
In the construction of a motor or dynamo it is desirable not only to keep the
resistance of the magnetic circuit as low as possible, but also to ensure as complete a
reaction as possible between the magnet and the conducting wire, in order that the
greatest number of lines of force may be converted with the least waste. To this end
the electric conductor should be disposed as close as possible to the iron, and should
be of the greatest possible length.
Another desideratum of the utmost importance is to so arrange the armature and
its coils, relatively to the field-magnet poles, that the field of force shall pass wholly
through the armature, so that no lines of force shall be wasted by leaking around the
armature instead of passing through its coils. It is also important to the economical
operation of such machines that the disposition of armature coils and field-poles shall
be such, relatively to one another, that the direction of the lines of force through the
coils shall be reversed as frequently as possible. The importance of this feature is
well understood with reference to the class of machines known as "flat ring" dynamos,
wherein it has been found that the multiplication of the field-magnet poles results in
a considerable gain in efficiency.
These general principles being well understood, I will now proceed to describe the
generic features of my presont invention.
My invention relates to electro-motors or dynamos of that class wherein a ring-
shaped armature is employed, wound with coils so connected as to generate two or
more contrary magnetic poles at different points around the ring, combined with a
field-magnet having its opposite poles arranged to correspond with the poles in the
armature. Armatures of this character are known to electricians as Grainne ring"
or "Paccinotti ring" armatures. They may be wound to develop only two poles,
at points diametrically opposite, or they may be so wound as to develop two or more
pairs of poles, the successive poles being of alternately-opposite polarities.
My invention aims, 1st, to enable the field-magnet to be made as short as possible ;
2nd, to enable the field-magnet to be given the utmost desirable area of cross-section ;
3rd, to simplify the field-magnet coil and to bring the greatest possible number of
turns thereof into the closest possible proximity to the field-magnet; 4th, to so arrange
the field-of-force relatively to the armature that the path of least resistance for the
lines of force shall be through the armature coils, thereby avoiding the wasting
of the lines of force by their escape around the armature; and 5th, to enable all
moving wire to be dispensed with, thereby greatly simplifying the mechanical con-
struction of the machine.
To enable the principle of my invention to be clearly comprehended I will com-
pare my improved construction with types of the constructions heretofore employed,
by aid of the diagrams, Figs. 1 to 5, which show the inagnetic elements alone, without
any winding of wire.
It is well known that in a dynamo or an electro-motor the magnetic circuit con-
sists of two parts, one comprised in the field-magnet and the other in the armature.
Throughout this circuit there exists, during excitation, the condition of strain known
as "magnetism," which develops itself along certain lines known as "lines of force."
These lines extend themselves through the iron of the circuit and stream across the
gap or space which (for mechanical reasons) is left between the field-magnet and
armature.
Fig. 1 shows the usual type of dynamo or electro-motor. A is the armature and F
is the field-magnet. The dotted lines show approximately the direction of the "lines
of force." Assuming that the armature is excited by a current through its coils (not
I

page_text: shown) it develops poles at opposite sides, and the lines of force issuing from these
poles are joined through the field-magnet F. This construction involves that the
field-magnet shall have a much greater weight and bulk than the armature, which
although not objectionable in a dynamo, is undesirable for an electro-motor. In
electro-motors the greatest efficiency for a given weight is attained by equally dividing
the weight between the armature and field-magnet.
Figs. 2 and 3 illustrate a known type of electro-motor. The ring-armature A is
here made of large diameter, and the field-magnet Fis arranged within it, crossing
diametrically from one side to the other, (see Fig. 2) entirely within the plane of the
armature (see Fig. 3). This construction has the disadvantage that the field-magnet
is too small, (having only one-third the weight of the armature) and that the polar
arc of the field-magnet is too large.
In either construction, either the armature or the field-magnet may rotate, it being
usual to make the lighter member the rotative one. Thus in Fig. 1 the armature
rotates, and in Figs. 2 and 3 it is the field-magnet that rotates.
Figs. 4 and 5 are diagrams illustrating the principle of my invention. Fig. 4 is a
face-view and Fig. 5 is a diametrical setion, cut from N to S.
A is the ring armature, of the Gramme type, and F is the field-magnet. The
magnetic circuit of the armature is closed by the field-magnet passing through the
armature from one side to the other, thereby crossing the plane of the armature.
Thus the field-magnet is arranged neither entirely outside of the armature, as in
Fig. 1, nor entirely inside the armature, as in Figs. 2 and 3; but it is partly outside
of and partly inside the armature. The middle portion of the field-magnet passes
through the center of the armature, being preferably parallel with the axis of
rotation, , and each end of the field-magnet extends thence radially, and
terminates at a a close to the armature, adjacent to one of the poles therein. Thus
the contrary poles of the field-magnet are on opposite sides of the plane of the
armature.
Fig. 6 is a view corresponding to Fig. 5, and showing the coils and electrical
connections for a very simple form of electro-motor. The ring armature A is wound
with coils cc according to the Gramme winding, and is fastened to a base-plate B.
Within it is fastened a stationary coil of wire E for exciting the field-magnet F. The
core 6 of the field-magnet is enclosed by this coil, but with a space between so that it
can revolve within the coil. The field-magnet is mounted on an axial shaft C, having
bearings in frames D D.
Since the armature is stationary and the field-magnet revolves it, is necessary to
make the commutator with stationary segments and revolving brushes. The segments e e
are fixed to one of the frames D, (but insulated therefrom) and conducting wires d d
lead from them to between the successive armature-coils c c. The diametrically-
opposite brushes ff which sweep the commutator-segments e e, are carried by
arms g g' which are fixed to the shaft C, and insulated from each other. The arm g
is connected to a sleeve h, and the arm g¹ is connected to a sleve h¹. Stationary take-
off brushes make contact with these sleeves respectively, and connect them with
the external circuit. The field-exciting coil E may be connected in this circuit in
series or derivation, or in a separate circuit, or by any known system.
When used as an electro-motor, the passage of a current through the coil E
magnetizes the field-magnet F. The passage of a current through the armature-
coils cc develops diametrically-opposite S and N poles in the armature at points
slightly in advance of the respective N and S poles of the field-magnet. The field-
magnet poles are consequently attracted toward the poles in the armature, and move
toward them, at the same time rotating the commutator brushes and thereby causing
the poles in the armature to move forward, away from the field-poles, so that the
rotation is maintained.
When used as a dynamo-electric machine the field-magnet will be rotated, and will
thereby induce electric currents in the armature coils, which currents will be collected
and rectified by the commutator in the usual manner.

page_text: In practice, it is desirable that the number of magnetic poles should be increased,
in order to bring the poles in the ring-armature closer together, as is well understood
with reference to "flat-ring dynamos." In Figs. 7 and 8 I have shown a construction
wherein four poles are employed, like poles being diametrically opposite, and contrary
poles 90 degrees apart.
Fig. 7 is a diametrical cross-section, and Fig. 8 is a face-view.
The field-magnet F consists of a core band arms a a extending radially from its
opposite ends, and terminating close to the armature on opposite sides. The two
north poles are on one side of the plane of the armature, and the two south poles are
on the other side. The poles are alternated, as shown in Fig. 7. Thus four distinct
"fields of force" are established, the lines of force extending themselves from each
N pole through the armature in both directions to the two S poles. The arrows in
Fig. 2 show the path of the lines of force in one of the four magnetic circuits.
It is thus seen that my invention introduces a radically new construction, which
presents the following advantages.
(1) The length of the magnetic circuit can be made less, and its aggregate cross-
section proportionally greater, than heretofore, thereby reducing magnetic resistance.
(2) The ideal proportions for an electro-motor of equal weight for the field-magnet
and armature are thus attained. (3) The field-magnet coil is simplified, and
the greatest number of convolutions brought into the closest possible proximity to the
field-magnet. (4) All moving wire is avoided, thereby greatly simplifying the
mechanical construction of the machine. (5) The "field of force'
" is so arranged
that the path of least resistance for the lines of force is through the armature coils,
thereby avoiding the wasting of lines of force by their escape around the armature.
And (6) the poles of contrary polarity are on opposite sides of the armature, so that
the reversals of magnetic polarity in the armature core are less extreme, and there is
less loss by heating.
These latter advantages may be best understood by a study of Fig. 9, which is a plan
of the armature and field-magnet poles developed in a straight line. The dotted lines
show the lines of force passing from the two N poles on one side of the armature, to
the two S poles on the opposite side. In consequence of the alternate arrangement
of the poles N S N S on opposite sides of the armature, and of the field-exciting coil E
within the armature, it follows that the path of least resistance for the lines of force
is through the armature core, since the reaction of the current in the coil E prevents
their passing across inside the ring armature, and the great resistance of the air
prevents their leaking around outside of the armature.
If we imagine the armature divided by a plane perpendicular to the axis of
rotation and cutting through its middle, we will understand that the half on the side
toward the N N poles presents a series of polarities the sum of which will be a
considerable S polarity, and that the side nearest the S S poles will have a con-
siderable N polarity. Thus the polar projections of the armature-core on one side
alternate between an approximately neutral condition and an extreme N polarity,
while those on the other side alternate between neutrality and extreme S polarity.
Thus there is in no part of the armature core a transition from one extreme of
polarity to the opposite extreme, as in the armatures of previous dynamos. Hence
my construction has less magnetic resistance in the armature, and less heating.
"I will now describe a fully developed and practical electro-motor, referring to
Figs. 10 to 16.
Fig. 10 is a front elevation thereof.
Fig. 11 is a side elevation.
Fig. 12 is a vertical section cut on the line 12-12 in Fig. 10.
Fig. 13 is a front view of the field-magnet removed.
Fig. 14 is a fragmentary section, cut along lines 14-14 in Figs. 10 and 15.
Fig. 15 is a fragmentary front elevation partly in section on line 15-15 in
Fig. 14.

page_text: The flat-ring armature A is of the Gramme winding, with four poles, and is
stationary. The field-magnet F has four poles, and is rotative.
On the base B are fastened two upright frames D D, which form bearings for the
axial shaft C. The short cylindrical core b is fastened on this shaft by set-screws or
otherwise, and two cross-pieces a' al are fastened against its opposite ends, as shown
in Figs. 12 and 13, or otherwise. To the opposite ends of the cross-pieces a¹ a¹ are
fixed polar blocks pp which come close to the opposite sides of the armature.
The armature A has an annular core ; of soft iron, which should be laminated
(Fig. 12) to avoid Foucault currents. It is best constructed by winding together
spirally a soft-iron ribbon and a strip of insulating material. The armature coils c c
are wound around this core in the usual manner. In the angular gaps between the
coils are inserted wedge-shaped pieces or teeth kk (Figs. 17 or 18) which constitute
the polar projections of the armature-core hereinbefore referred to.
The field-magnet-coil E is wound within the ring armature as shown in Fig. 12.
It is fastened to the armature, and supported thereby. Two disks are placed against
its opposite ends and are fastened peripherally to two rings m m which fit over its
periphery and are drawn together against the opposite sides of the armature, by screws
or bolts n n.
The armature is fixed solidly to the frames D D in the manner shown in Figs. 14
and 15. The frames D D are fastened by screws qq to four cross-bars L L, which
pass through the gaps between the armature coils cc, and touch the periphery of the
armature core. Angular plates rare fitted into the gaps on opposite sides of the
core, and fastened by insulated bolts which pass through the core.
2°
is then screwed to the plates r r by insulated screws.
The cross-bar L
The field pole-pieces a a revolve in the spaces between the frames D D and the
armature and field-magnet coil. The polar blocks p p are so thick as to bring their
inner faces close to the sides of the armature (Fig. 12); and their forward and rear
edges are made with oblique outlines (Fig. 10); so that as the poles advance their
forward edges will shear obliquely across the core projections k k of the armature.
Thus the concentrated lines of force streaming across between their forward edges
and the core projections will, as the polar block encounters each new projection k,
move inward along the advancing oblique edge of the block whereby the magnetic
pull is rendered more continuous than heretofore.
The magnetic parts may be housed in, in order to protect them from dust and
obstructions, in the manner shown in Figs. 14 and 15. Thin disks t t of insulating
or non-magnetic material are placed against the frames D D, and a tubular band s, of
insulating or non-magnetic material, is placed around the periphery of the armature,
and fastened by screws to the flattened ends of the arms of the frames D D.
The commutator consists of stationary segments ee and rotating brushes ff. In
the construction shown the armature has 24 coils c c, and the commutator has
24 segments e e, connected respectively by 24 wires d d with the connecting terminals
between the several armature coils, as usual. There are two brushes ff in connection
with the positive binding post, and two brushes f1 f¹ in connection with the negative
binding-post. Thus the current flows through the armature in derivation. But if
it is preferred to use the current undivided, only two commutator brushes will be
used, and the armature coils will be connected accordingly in any manner employed
in the construction of "flat-ring" dynamos.
The positive brushes ff are carried by arms g g on a hub which is fastened to the
shaft C. The negative brushes f¹ f' are carried by arms g¹ g' on a hub h', which is
mounted over the hub h but insulated therefrom. Two take-off brushes or metal
strips make contact respectively with the hubs h and h¹, being pressed apart and
against them by an insulated screw n'. The strips i¹ are fastened respectively to
two insulated standards o and o¹ (Fig. 10) which constitute the terminals or binding-
posts for the wires.
An electro-motor requires means for stopping, starting and reversing it. In my
machine there is a lever H by moving which the position of the commutator segments
may be shifted, thereby altering their relation to the brushes and consequently changing

page_text: the relative positions of the armature poles. The segments e e are fastened to an
insulating disk G, which is fastened to the lever H. In Fig. 10 the lever H is shown
in its mid-position, which it occupies when the machine is at rest. To cause the
machine to run forward the lever H is moved to the position indicated by the dotted
line H¹ in Fig. 10; and to reverse the machine the lever is moved to the position
denoted at H. To permit the commutator segments to be moved to this extent the
conducting wires d d are made flexible and sufficiently slack. In small machines
I divide the 24 wires d d into four groups, assemble together the six wires of each
group, and unite them by a suitable covering into a flexible cable v, which is fastened
at one end by a clamp u.
To retain the lever H in any position, it is provided with a spring_latch which
engages a curved rack-bar I, which is fastened to the front frame D. The peculiar
construction of this latch is best shown in Figs. 10 and 16. A latch lever Qis
pivoted by a screw w to the lever H and carries an adjusting screw or worm J. A
spring y acts to press down the worm J into mesh with the teeth of rack I. By
pressing the upper arm of lever Q toward the lever H as shown in Fig. 16, the worm
is lifted clear of the rack and the lever H may then be moved to any position desired.
Any minute adjustment of the commutator may then be made by turning the milled
head .J' of the worm J. If desired the worm J may be made differential by forming
its stem with a screw-thread of finer pitch, screwing in the head of the pivot w, as
shown in Fig. 16.
Fig. 17 shows the preferred construction of the armature core projections kk.
They are made hollow or trough shaped, so as to present two edges of metal to the
inductive action of the field-poles. The construction shown consists of two pieces
of angle iron fitted together and placed against the armature core, as shown in
Fig. 11, a piece of insulating material being interposed between the base " and the
bare iron of the core, to prevent Foucault currents. The opposite wedges k k are
fastened to the core in pairs by bolts z which should be insulated.
2
The hollow wedges k may be made in various ways. Fig. 18 shows one both sides
of which are bent up from one piece of iron plate. Fig. 19 is an end view of another
construction showing the sides reinforced in thickness by clamping pieces of iron
against them. These wedges may be laminated, or made of two or more thicknesses
of sheet iron.
By making these wedges k hollow, so that they present two walls or edges k¹ k¹ to
the pole pieces a a of the field-magnet, the lines of force are so distributed that an
advancing pole piece is first attracted chiefly by the lines of force streaming across
from the wall or edge nearest it, and as it advances to where it overlies that edge and
is attracted in a less degree thereby, new lines of force will spring to it from the other
edge, and will further attract it.
Figs. 20 and 21 show another construction for accomplishing the same result,
which is especially adapted to large armatures wound with numerous coils. In this
construction the troughs k k are parallel. Two of them are laid against the core on
opposite sides (Fig. 20) and the coil is wound around the core in these troughs,
thereby fastening them securely to the core. In order to fasten the armature to the
cross-bars L, two of the troughs have wedge-shaped blocks of metal r fastened
between them on each side of the core, and are fastened thereto by screws or rivets.
The cross-bar L is then fastened to the blocks rr, as shown in Fig. 21.
My improved electro-motor thus described is simple in construction, compact, not
liable to get out of order, is easy to adjust and control, and develops a high efficiency.
Its weight is less in proportion to the power that it develops than that of any previous
electro-motor.
I will now describe some modifications of my invention.
Fig. 22 is a front elevation of a 12 pole machine and Fig. 23 is a vertical transverse
section thereof cut on the line 23-23.
In this construction the field-magnet is of much larger diameter, and its core b is
expanded into a large tube, which is confined between the end plates or disks a' a'.
Each of the plates al is formed with six pole pieces a a, the poles on one side of the

page_text: armature being arranged mid-way of those on the other side, as shown in Fig. 22. The
armature is wound with more coils, since it has 12 poles instead of 4. The
commutator (not shown) will be modified accordingly, as any practical electrician
will understand.
Fig. 24 is a vertical mid-section illustrating another modification. In this con-
struction the field-magnet is stationary and the armature rotates. The shaft C is
screwed fast to the frames D D and the field magnet F is fixed to it. The armature A
is mounted within a case P, the outer part of which may be used as a belt pulley.
The two disks P¹ P1 on opposite sides of the case P are formed with hubs which
rotate on the fixed shaft C. The commutator segments e e are carried by one of the
disks P¹; and the commutator brushes are stationary. The field-magnet coil E is
wound directly on the field-magnet core and remains stationary.
My invention is applicable to magneto-electric machines by simply omitting the
coil E and making the field-magnet F a permanent magnet.
In order to construct a dynamo electric machine according to my invention no
alterations are necessary except in matters of proportion. For example, it is desirable
to increase the number of convolutions in the field exciting coil, and to increase the
mass of the field-magnet or reduce proportionally that of the armature.
I make no claim in this application to anything claimed in another application
which I have made for a patent for "Improvements in Dynamo-Electric Machines
and Electro-Motors," No. 15858 of 1887.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
In an electro-motor or dynamo (or magneto) electric machine, the following defined
novel features :-
1. The combination with a ring armature of the Gramme type, of a field-magnet
extending through the open center thereof from one side to the other and having its
contrary poles disposed adjacent to the armature on opposite sides thereof.
2. The combination with a ring armature of the Gramme type, of a field-magnet
having its middle portion or core extending through the open center of the armature
in a direction substantially parallel with the axis of rotation, and having pole-pieces
extending from the ends of the core radially and terminating adjacent to the armature
on opposite sides thereof, the poles of one polarity being disposed on one side of the
armature and those of the contrary polarity being arranged in alternation therewith
and on the opposite side of the armature.
3. The combination with a ring armature of the Gramme type, of a field-magnet
having its middle portion or core extending through the conter of the armature in a
direction substantially parallel with the axis of rotation, and having its contrary
poles disposed adjacent to the armature on opposite sides thereof and arranged in
alternation, and an exciting coil for said field-magnet arranged within the armature
and enclosing said core.
4. The combination with a non-rotative ring armature of the Gramme type, of a
rotatively mounted field-magnet extending through the open center of the armature,
and having its contrary poles disposed adjacent to the armature on opposite sides
thereof and arranged in alternation, each pole being disposed midway of two poles of
the contrary polarity.
5. The combination with a non-rotative ring armature of the Gramme type, of a
non-rotative field-exciting coil fastened within said armature, and a rotatively mounted
field-magnet extending through the center of the armature and field-coil and having
radial pole-pieces extending past the ends of the field-coil and terminating adjacent
to the armature on opposite sides thereof, whereby all moving wire may be avoided.
6. The combination with a ring armature of the Grammne type of a field-magnet
extending through the open center thereof and having its contrary poles disposed
adjacent to the opposite sides of the armature and arranged in alternation, said magnet

page_text: being constructed of a central axial core and end pieces forming the poles fastened
removably to the opposite ends of said core.
7. The combination with a ring armature of the Gramme type, of a field-magnet
consisting of a cylindrical core b, two opposite end pieces a¹ a¹ fastened removably to
the ends thereof and forming radial pole-pieces, and polar blocks p p fastened to said
end pieces.
8. The combination with a ring armature of the Gramme type, of a field-magnet
having its contrary poles disposed adjacent to the armature on opposite sides thereof
and arranged in alternation, whereby the lines of force proceeding from one pole to
the next pole of contrary polarity enter the armature core at one side and pass out at
the side opposite to that by which they enter.
9. A ring armature of the Gramme type constructed with an iron core wound with
radial coils and having core projections in the angular spaces between the coils, each
of said core projections made so as to present two walls or edges at the side of the
armature, one in advance of the other.
10. A ring armature of the Gramme type constructed with an iron core wound
with radial coils and with iron core projections in the angular spaces between the
coils, said core projections projecting laterally to the opposite sides of the armature
in the form of walls perpendicular to the plane of the side of the core, and the two
walls in each angular space separated from one another, thereby forming an angular
recess between them.
11. A stationary ring armature of the Gramme type in combination with a field-
magnet revolving with its poles on opposite sides thereof, and with two fixed frames
on opposite sides of the armature and exterior to the revolving field-magnet, and
connections for uniting said armature to said frames consisting of cross bars extending
between the frames and crossing the periphery of the armature core perpendicularly
thereto, and angular plates fitted against opposite sides of the core between the
armature coils, to which plates said cross-bars are fastened.
12. A ring armature of the Gramme type, in combination with a revolving field-
magnet, with the fixed frame of the machine to which the armature is rigidly
connected, with a stationary field-coil within the armature, and with connections for
fastening said coil to the armature consisting of rings fitting over the field-coil and
against opposite sides of the armature, and screws for fastening said rings together.
13. The combination with the Gramme ring armature A having polar projections
in the angular spaces between its cores, of a field-magnet having polar blocks p p
formed with inclined advancing edges so as pass obliquely over said core projections.
14. In an electro-motor the combination of a toothed rack I with a controlling
lever H, a latch Q pivoted thereto, and a worm J mounted in said latch, adapted to
engage the teeth of said rack when the latch is pressed down and to be raised clear
therefrom when the latch is retracted.
All substantially as set forth in the foregoing specification.