readily than if he does it in a hired office like that
which the "Nautical Almanac" then occupied. My continued presence
on the observatory staff led to my taking part in two of the great
movements of the next ten years, the construction and inauguration
of the great telescope and the observations of the transit of Venus.
But for the time being my connection with the regular work of the
observatory ceased.

On the retirement of Admiral Sands in 1874, Admiral Davis returned
to the observatory, and continued in charge until his death in
February, 1877. The principal event of this second administration
was the dispatch of parties to observe the transit of Venus. Of this
I shall speak in full in a subsequent chapter.

One incident, although of no public importance, was of some interest
at the time. This was a visit of the only emperor who, I believe,
had ever set foot on our shores,--Dom Pedro of Brazil. He had
chosen the occasion of our Centennial for a visit to this country,
and excited great interest during his stay, not only by throwing
off all imperial reserve during his travels, but by the curiosity
and vigor with which he went from place to place examining and
studying everything he could find, and by the singular extent of
his knowledge on almost every subject of a scientific or technical
character. A Philadelphia engineer with whom he talked was quoted
as saying that his knowledge of engineering was not merely of the
ordinary kind to be expected in an intelligent man, but extended
to the minutest details and latest improvements in the building of
bridges, which was the specialty of the engineer in question.

Almost as soon as he arrived in Washington I received the following
letter by a messenger from the Arlington Hotel:--

Mr.:
En arrivant a Washington j'ai tout-de-suite songe a votre
observatoire, ou vous avez acquis tant de droit a l'estime
de tout ceux qui achevent la science. Je m'y rendrai donc
aujourd'hui a 7 heures du soir, et je compte vous y trouver,
surtout pour vous remercier de votre beau memoire que j'ai
recu peu avant mon depart de mon pays, et que je n'ai pas
pu, par consequent, apprecier autant que je l'aurais voulu.
En me plaisant de l'espoir de vous connaitre personnellement
je vous prie de me compter parmi vos affectionnes.
D. Pedro D'Alcantara.
7 Mai, 1876.

Like other notes which I subsequently received from him, it was in
his own autograph throughout: if he