Nov. 23.]
THE NEW ZEALAND GAZETTE.
1759

necessary dimensions in figures, so that the
sketch or drawing could be worked from.
(c.) He must also be able to take off and calculate
indicator diagrams.
(d.) He must be able to calculate safety-valve
pressures, and the strength of the boiler, shell,
stay, and riveting.
(e.) He must be able to state the general pro-
portions borne by the principal parts of the
machinery to each other, and to calculate the
direct strain, the twisting strain, and the
bending strain in rectangular bars, and in
round bars with given loads.
(f.) He must be able to explain the method of
testing and altering the setting of the slide
valves, and to sketch about what difference
any alteration in the slide valve will make in the
indicator diagram, and of testing the fairness
of the paddle and screw shafts, and of adjusting
them.
(g.) He must be conversant with surface con-
densation, superheating, and the working of
steam expansively.
(h.) His knowledge of arithmetic must include
the mensuration of superficies and solids and
the extraction of the square root, and the ap-
plication of these rules to questions relating
to the power, duty, and economy of engines
and boilers, and to the strains in rods, shafts,
and levers of the engine.

EXAMINATION FOR AN EXTRA OR HONORARY
CERTIFICATE.

31. An Extra First-class Engineer's Examination
    is voluntary, and is intended for such persons as
    wish to prove their superior qualifications, and are
    desirous of having certificates equivalent to those of
    the highest grade granted by the Marine Department.
32. The extra examination may take place at the
    time the candidate goes up for a first-class engineer's
    certificate, or at any time subsequent to his having
    passed as first-class engineer.
33. The examination can generally be held at any
    port where examinations of engineers are ordinarily
    conducted and on the same days, but notice must
    be given by the applicant at least one week before
    the day on which the examination begins. When
    extra examinations cannot be held due notice will
    be given.
34. If the candidate passes, he will be entitled to
    receive the extra certificate at once without being
    required to have served two years at sea as first-
    class engineer with a first-class engineer's certificate
    of competency as heretofore.
    (a.) The candidate must possess a thorough
    knowledge of the construction and working
    of the different forms of marine engines and
    propellers in all their parts, and be so far
    acquainted with the elements of theoretical
    mechanics as to comprehend the general prin-
    ciples on which the machine works, and to
    illustrate his knowledge of these principles
    by numerical examples.
    (b.) He must possess a knowledge of the theory
    of strain and stress sufficient to be able to
    deduce the ordinary rules for twisting and
    bending of round and rectangular bars.
    (c.) He must be acquainted with the principles
    of expansion and the modern theory of heat,
    and be able to solve, with the assistance of his
    own books or without books, according as the
    examination papers may be set, the principal
    questions in economy and duty in connexion
    with engines and boilers.
    (d.) He must understand how to apply the indi-
    cator, and to draw the proper conclusion from

the diagrams, and to construct the approxi-
mate diagrams for any given data.
(e.) He must be able to produce without a copy
a fair working drawing of any part of the
machinery with figured dimensions fit to work
from.
(f.) He must understand the principles of the
action of the screw-propeller and the paddle-
wheel, and he must be able to estimate nume-
rically the effect in speed of ship and con-
sumption of fuel due to any alteration in
pitch, diameter, revolutions, &c.
(g.) He must be able to give a description of
boilers and the methods of staying them, and
he must show that he possesses a knowledge
of theoretical principles which regulate their
construction, and that he is able to calculate
the strength of the boiler shell, stays, and
riveting.
(h.) He must understand the general nature of
the strains and stresses produced by the
steam pressure, and by the expansions due to
unequal temperatures in boiler shells.
(i.) He must have a knowledge of safety-valve
construction, and the principles involved in
determining the size of a safety-valve, and the
construction of spring-loaded and dead-weight
valves.
(k.) He must possess a thorough knowledge of
the theory of combustion, the chemical com-
position of fuels, the evaporative duty of
fuels of given composition, the production
of draught, the effect in regard to economy,
safety, and wear and tear, of increasing or of
diminishing the proportion of heating surface,
of grate-bar surface, of area of section of air
passages, of area of water surface, of steam
space capacity and water capacity.
(l.) He must be able to explain the formation of
scale and the precipitation of salt, and the pre-
cautionary means adopted in respect thereto,
with jet condensers and with surface con-
densers.
(m.) He must understand the general principles
involved in the construction of the barometer,
thermometer, salinometer, and steam and
vacuum gauges.
(n.) He must be familiar with the general re-
sults obtained from past experience in relation
to corrosion, pitting, and galvanic action in
boilers.
(o.) He must give a variety of illustrations of
how defects have arisen from accident, imper-
fect construction, or deterioration, and how
these defects might have been prevented, and
the best way of repairing such defects.
(p.) He must possess an intelligent knowledge
of the properties of the lubricants, boiler
cements, and indiarubber in general use in
steamers.
(q.) He must understand the causes of spon-
taneous combustion and the formation of
explosive gases in coal holds, and the pre-
cautionary measures proper to prevent acci-
dents from these causes.

FEES.

35. Candidates for examination, in making their
    application on Form Exn. 3, will be required to pay
    the examination fee before any step is taken, whether
    by inquiring into their services or testing their quali-
    fications, &c. Should it be found that their service
    is not sufficient to entitle them to be examined, or
    should their testimonials be unsatisfactory, or should
    they from any other cause not be examined, no part
    of the fee will be returned to them; but when they