Marcu 21, 1912] 
NATURE 
15 
The sizes, weights, and speeds chosen are such as 
to result in a compass having many times the direc- 
tive force of a magnetic compass, and therefore re- 
sponding to much smaller alterations of direction 
than can readily be observed with a magnetic com- 
pass. The compass itself being quite non-magnetic, 
can be put down under armour—in a position where a 
magnetic compass could work only with very special 
precautions and under grave difficulties. The action 
of the contact is to control a small electric motor, 
which moves a plate away from the contact on the 
card as soon as it touches it, and then the motor 
stops; the motor drives a transmitting device which 
controls as many receivers as are wanted in the ship. 
The receivers are merely electrical counters, and can 
be put in any position; the small dials make one com- 
plete revolution for only 10° change of course, and 
these are geared after the manner of clock-hands to 
the outer dial, one turn of which corresponds to a 
turn of thirty-two points, or 360°; they are arranged 
to turn at a quicker rate than any large ship can turn 
in the water. The movement which the inner card 
makes, for a very small alteration of course, is con- 
siderable, and takes place instantly; and, owing to 
this fact, enormous improvement is possible in the 
steering of a large ship when the helmsmen have 
become used to the appearance of the dials. 
Attention must be paid to the necessity of correc- 
tions which have to be applied to the readings of the 
compass. 
The first correction is an interesting one, as it is not 
apparent at first sight; it is common to every form of 
evrostatic device which takes the earth's rotation into 
consideration. If a ship with a gyro compass is 
steaming due east or due west, the ship’s speed is 
added to the speed of rotation of the earth in space, 
or deducted from it. Suppose the ship steams due 
north, then the resultant travel of the ship in space 
is along the diagonal line, as it is moving from west 
to east by the earth’s rotation, and south to north 
by its own steam. Therefore it is travelling in space 
about some axis which it sets its own axle and its 
N. and S. line on the compass card, parallel to 
which is not the north and south axis of the earth. 
The speed of the ship, the course and the latitude, 
come into this correction, for which tables are made 
out, the maximum correction which has to be con- 
sidered being some 3°; for all manceuvring this cor- 
rection can be neglected. 
The second correction which has to be taken into 
account is due to the existence of the air blast used in 
damping, the damping checking the precession when- 
ever this takes place. The precession varies with the 
cosine of the angle latitude; the air blast is constant 
in its effects in all latitudes, depending only on the 
speed of rotation of the gyro—therefore there is a 
varying cause and a constant retarding force, and in 
consequence a varying result. The effect is that for every 
10° of latitude a correction of about 3° has to be 
applied—4° in a distance of 600 miles. 
The gyro compasses in use in the British navy are 
adjusted to be correct at 50° north latitude, so that 
for all cruising in the Channel and say up to the Firth 
of Forth, this correction does not require considera- 
tion. 
Both these corrections gan be treated arithmetically 
by adding to or deducting from the reading on the 
card the same quantity all the way round; it does 
not vary in different parts of the card, as is the case 
when applying a deviation correction to a magnetic 
compass reading. 
The worst difficulty which the gyro compass is faced 
with is the effect produced by violent rolling or great 
vibration in a ship. This has been receiving a great 
NO. 2212, VOL. 89| 
amount of attention from 
eighteen months, since 
the inventors during the last 
practical experience at sea 
showed the necessity of some improvements in this 
respect. Fortunately the results of the investigations 
have led to considerable improvement, and to a com- 
plete cure of the trouble experienced in this way, so 
that it will shortly be possible for gyro compasses 
to be installed in ships which are quite independent 
of the rolling motion or vibration of the vessel. 
UNIVERSITY AND EDUCATIONAL 
INTELLIGENCE. 
Lonpon.—TIwo important  benefactions were 
announced last week. The first is an offer of 
1oo,oool. from an anonymous friend of the University, 
made through Lord Haldane as chairman of the 
Royal Commission on University Education in 
London, as a contribution towards the cost of acquir- 
ing the vacant site north of the British Museum for 
new University headquarters. This munificent offer, 
announced last Friday, was followed next day by an 
offer from the Drapers’ Company to erect a Senate 
| House and administrative offices at an approximate 
cost of 60,0001. The offer is not explicitly associated 
with the site mentioned above, but it is based on the 
report of the Royal Commission, which suggested a 
building such as is indicated, together with other 
buildings appropriate to the site, which is divided into 
four plots. The Drapers’ Company stipulate that the 
other buildings are to be provided within a reasonable 
time. In connection with the gift of 100,000l., a 
| board of trustees has been formed, composed of Lord 
_ deal 
Haldane, representing the Government; Lord Milner, 
representing the Royal Commission; Lord Rosebery, 
representing the University; and Sir Francis Trippel. 
It is stated that the donor has already done a great 
for university education, and holds that the 
University of London ought to be the chief educa- 
tional institution of the Empire. 
Giascow.—The Vice-Chancellor, Sir Donald 
MacAlister, K.C.B., has been appointed by the Uni- 
versity to represent it at the fifth jubilee festival of 
the Royal Society. 
The centenary of the launch of the Comet as a 
passenger steamer on the Clyde is to be celebrated 
during the summer. Prof. Barr, of the chair of 
engineering, and Prof. Biles, of the Elder chair of 
naval architecture, are the University representatives 
on the centenary committee. 
Mr. J. M. F. Drummond, appointed lecturer in 
botany, is to have special charge of plant physiology. 
The fine collection of prehistoric antiquities recently 
displayed in the Glasgow National Exhibition has 
been deposited by Mr. Ludovic Mann in the 
Hunterian Museum. 
Proposals are under consideration for the erection 
within the University of a monument of the famous 
Glasgow brothers, John and William Hunter, the 
latter of whom was the founder of the Hunterian 
Museum. 
Ir is announced in Science that gifts of more than 
1o0,0001. to the University of California have just 
been secured through the will of the late Mrs. Jane 
K. Sather, of Oakland. Plans have been begun for 
the Sather Campanile, a lofty bell-tower, for which 
Mrs. Sather provided some 40,000/. Two professor- 
ships are endowed, and endowment is provided for 
three book funds. 
Dr. H. L. Situ has accepted a call to the presi- 
dency of Washington and Lee University, Lexington, 
Virginia, and will probably enter upon the duties of 
