George Biddell Airy

“ I entirely approve of education of young women to a higher pitch than they do commonly reach. I think that they can successfully advance so far as to be able clearly to understand—with gratification to themselves and with advantage to those whose education they will superintend—much of the results of the highest class of science which have been obtained by men whose lives are in great measure devoted to it. ”

“ Therefore, in order to ascertain what is the curvature of an orbit, we must consider not only the amount of the sun's attraction at any part of it, but also what is the amount of velocity with which the planet is moving at that point. If, then, it can be shown that when the planet is nearest to the sun it moves with a greater velocity, it will follow that, though the attractive force is greater than when farthest from the sun, its orbit may not be more curved than when it is farthest from the sun. ”

“ It is not simply that a clear understanding is acquired of the movements of the great bodies which we regard as the system of the world, but it is that we are introduced to a perception of laws governing the motion of all matter, from the finest particle of dust to the largest planet or sun, with a degree of uniformity and constancy, which otherwise we could hardly have conceived. Astronomy is pre-eminently the science of order. ”

“ The only instrument which, as I think, may possibly be called for by the demands of the astronomer or the astronomical public, is a telescope of the largest size, for the observation of faint nebulae and minute double stars. Whether the addition of such an instrument to our apparatus would be an advantage, is, in my opinion, not free from doubt. The line of conduct for the Observatory is sufficiently well traced; there can be no doubt that our primary objects ought to be the accurate determination of places of the fundamental Stars, the Sun, the Planets, and, above all, the Moon. ”

“ Now, the statement that the sun appears to move in a great circle on the globe amounts to this: that the sun appears to move in a plane which passes through the earth. For all globes represent the stars as they would appear if the observer were at the centre of the globe; and a great circle is one whose plane passes through the centre of the globe. If we found that the sun was describing one of the smaller circles on the globe, then we should say the sun was not moving in a plane round the earth. ”

“ We had all but one feeling of the purest pleasure in the prospect of the true domestic comfort to which we fully believe you to be now gone, and we rejoice that all your endearing qualities will now be employed to promote the happiness of one whom we think so worthy of them as your dear husband, who has left us in the best opinion of his good heart, as well as his enlightened and sound understanding. ”

“ I have here spoken repeatedly of our supposition that some stars are nearer to us than others. The grounds of this supposition are generally the amount of what is called the proper motion of the stars. Upon comparing the places of the stars, as we observe them in different years, and applying the corrections for precession, nutation, and aberration, so as to reduce every observation of every star to what it ought to exhibit on the first day in the year, agreeably to the common practice of astronomers, we find that a great number of the stars have what is called proper motion. ”

“ I much desire to see the system of time-signals extended, by clocks or daily signals, to various parts of our great cities and our dockyards, and above all by hourly signals on the Start Point, which I believe would be the greatest of all benefits to nautical chronometry. Should any extension of our scientific work ever be contemplated, I would remark that the Observatory is not the place for new physical investigations. It is well adapted for following out any which, originating with private investigators, have been reduced to laws susceptible of verification by daily observation. ”

“ The knowledge derived from Lectures is exceedingly imperfect: that derived from careful reading is admirable for its accuracy and fulness, but occupies the mind rather as a train of internal ideas than as a series of consequences deduced from the observations of nature: but that inferred from actual personal observation carries with it a degree of reality and certainty, as the veritable science of external objects, which nothing else can give. ”

“ I believe that, in addition to the effects ascribable to Newtonian gravitation (as general motion of the earth, precession of the equinoxes, and tides) , this magnetic disturbance is the only one yet established as depending on an external body. Men in general, however, do not think so. It appears to be a law of the human mind, to love to trace an effect to a cause, and to be ready to assent to any specious cause. Thus all practical men of the lower classes, even those whose pecuniary interests are concerned in it, believe firmly in the influence of the moon upon the winds and the weather. ”

“ It is indeed the great and fundamental principle of Astronomy, that the stars do move as if they were attached to a shell, or in other words, that they move all in a piece. As to the explanation of that, I shall not trouble you at present. I simply call attention to the fact, that the stars move all in a piece—either that they are connected with some one thing turning upon an axis, or that they stand still while the earth turns round an axis of its own ”

“ TRINITY COLLEGE, CAMBRIDGE, May 10, 1872.
MY DEAR AIRY, I have received your card of invitation for the 1st of June, and with great joy should I count upon that day if I thought that I should be able to accept your invitation: but alas I have no hope of the kind, for that humiliating malady which now has fastened upon me for a full year and a half has not let go its hold, nor is it likely to do so. A man who is journeying in the 88th year of his pilgrimage is not likely to throw off such a chronic malady. ”

“ Now, remember how it has been explained that the curvature of a planet's orbit, or the curvature of the path of a cannon ball, depends upon two circumstances; one is the velocity with which it is going, and the other is the force which acts in such a direction as to bend its path. The greater its speed, the less its path is curved; consequently, as the planet is going so exceedingly quick in the neighbourhood of K, its orbit may be very little curved there, even though the sun is there pulling it with a very great force. ”

“ Whereas Geometry (of course to an intelligent student) is a real inductive and deductive science of inexhaustible extent, in which he can experiment for himself—the very tracing of a curve from its equation (and still more the consideration of the cases belonging to different values of the parameters) is the construction of a theory to bind together the facts—and the selection of a curve or surface proper for the verification of any general theorem is the selection of an experiment in proof or disproof of a theory. ”

“ I trust that I am doing well in rendering Greenwich, even more distinctly than it has been heretofore, the place of reference to all the world for the important observations, and results of observations, on which the system of the universe is founded. As regards myself, I have been accustomed, in these matters, to lay aside private considerations; to consider that I am not a mere Superintendent of current observations, but a Trustee for the honour of Greenwich Observatory generally, and for its utility generally to the world ”

“ I have spoken continually of the sun's attraction upon the earth and of the earth's revolution round the sun, as if the sun were the only body whose attraction influenced in a material degree the earth's movement. But in reality the moon also acts in a very sensible degree upon the earth. And the immediate effect upon the motion of the earth is found by proper investigation to be the following. ”

“ ROYAL OBSERVATORY, GREENWICH,
LONDON, S.E.,
1866, May 5.
MY DEAR SIR, The MS. concerning Colenso duly arrived.
I note your remarks on the merits of Colenso. I do not write to tell you that I differ from you, but to tell you why I differ.
I think that you do not make the proper distinction between a person who invents or introduces a tool, and the person who uses it.
The most resolute antigravitationist that ever lived might yet acknowledge his debt to Newton for the Method of Prime and Ultimate Ratios and the Principles of Fluxions by which Newton sought to establish gravitation. ”