Feldhausen near Wynberg <1>
Jany 29. 1837
My dear Sir,
Some little time before my departure from England, I remember your expressing a wish to procure specimens of Cape Plants, bulbs, Seeds &c – and from something which occurred, I was led to suppose that I might hear from you respecting the engaging a person on the spot to collect for you. As that however has not been the case, of course I have taken no step of the kind – though should you still wish it, I am ready to act as you shall authorise me.– Meanwhile I take the opportunity afforded me by the departure of my friend Dr. Andrew Smith <2> Assist Staff Surgeon here, (the ardent and enterprising conductor of the Expedition lately returned from Exploring the Countries to the North part of this Colony) to transmit you a few specimens of Bulbs of my own collecting & which I have cultivated in a little Botanical Garden of my own, on a very humble scale – & which though probably neither very new nor very rare, yet having been taken up just at the proper time, and being quite fresh and vigorous, may perhaps repay the trouble of planting out should they escape wetting by the way, which as Dr Smith has kindly offered to make them objects of his especial attention, will I dare say be the case.
I am very glad of this opportunity to introduce Dr Smith to your personal acquaintance as one of the most zealous and disinterested cultivators of natural Science – especially of the branches of Zoology and Natural History. The difficult and adventurous journey from which he has returned, and the rich & rare products which he has collected sufficiently testify to the former feature of his character – while the latter is no less evident by the object of his return to England, which is expressly that of publishing his results (assisted, if possible, by the British Government) and Exhibiting and ultimately disposing of his collections – not for his private advantage, but for the sole and express purpose of enabling an Association formed here at his instance (under the title of the South African Asscn for Exploring Central Africa) to fit out a second Expedition to proceed further in the same direction. Of this, should it be organised, he will of course be called upon to take the command, an arduous and perilous service, but towards which all the energies of his mind are devoted.
You have it in your power to be of real service to Dr Smith & to the cause in which he has embarked by making known these objects & motives (which it is highly important to have distinctly understood) in circles where it is most desirable they should be properly appreciated, as well as by affording him introductions to such of your Scientific and other friends as you think likely to take an interest in these departments of research.–
I am very glad to percieve by the notices which reach me from time to time of what is going on in the Scientific world in England that you continue to cultivate (and that too with real and brilliant success) those pursuits, both theoretical and experimental in which, before I quitted England, you had already done so much to distinguish yourself. I trust you will feel yourself now too deeply pledged in this career to abandon it and that we may look upon these things as the earnest of still greater & more important discoveries both in mathematics and photology. <3>
I have now nearly completed my examination of the Southern hemisphere, every part of which (with exception of a few trifling lacunæ which this summer will fill up) has now been gone over at least twice and an enormous collection of objects observed which I am now occupied in reducing & arranging.
The Spots in the Sun are new & have been very interesting and their observation has fully confirmed me in an opinion I had expressed in a note appended to an article of my “Astronomy” <4>– viz: that they originate in the Suns rotation on its axis combining with some cause extraneous to that luminary.– That cause I apprehend to be an unequal emission escape of heat from its equatorial and polar regions – due either to non imperfect transparency (or as folks now call it [illegible deletion] diathermaneity*) of a lenticular ethereal envelope of which the Zodiacal light may possibly be an exterior & visible portion – or to an aërial atmosphere of the Sun itself, superior to the luminous clouds, and more oblate in form than the body of the Sun so as to offer a greater resistance to the radiation of both heat & light in the Equatorial than in the polar regions. In this last view of the Subject the concomitant cause would not be, strictly speaking an extraneous one, some such increase of oblateness in the exterior shells of the solar atmosphere would be a consequence of the Equilibrium of its strata under the conditions of its rotation – In either however the effect in question would arise, by the Establishment of circulating currents analogous to trade winds accompanied (as on the Earth) by local Hurricanes & Tornadoes about the border of the tropical regions – But more of this elsewhere.–
At present I must subscribe myself My dear Sir Yours very truly
J.F.W. Herschel
*? would not transcalescence be a preferable word.
Notes:
1. Feldhausen was Herschel’s house and observatory at Wynberg (Cape Town).
2. Sir Andrew Smith (1797–1872), served as a military surgeon at the Cape of Good Hope 1821–1837 and was successful in returning to lead an expedition into Africa.
3. ‘Photology’ was used for a short time in the nineteenth century, most often by Herschel, to denote the entire science of light and optics. He had first used it in a letter to Dr Daubeny 12 June 1832, published as ‘On the Action of Light in Determining the Precipitation of Muriate of Platinum by Lime-water …’, Pilosophical Magazine, v. 1 no. 1, July 1832, pp. 58–60. See also Herschel, ‘Light’, Familiar Lectures on Scientific Subjects (London: A Strahan, 1866).
4. Herschel, ‘Physical Astronomy’, Encyclopaedia Metropolitana, 2nd Division, Mixed Sciences, v. 1, 1829, pp. 647–729.