A Certain Phaenomenon, Seen by Monsieur Havelius, Feb. 5. 1674. St. No. not Far from Marienburg in Boroussia -about the Sun a Little before His Setting and the Moon's Conjunction, and the Sun's Eclipse, (Which Yet Was Not Seen by Him.)

A Note about some unusual Diamonds. There came to our hands, some while since, a Representation of a considerable number of excellent Diamonds, sold by one Monsieur Tavernier to his King, after his last return from the East-Indies, whether he had made six Voyages by Land. Amongst these Diamonds there are described three of a very unusual colour; one weighing 112½ Carats, of a very fine Violet-colour, and two of a Rose-pale colour all three of an Adamantin hardness, and upon that account esteemed Diamonds. A certain Phenomenon, seen by Monsieur Havelius, Feb. 5. 1674. St. No. not far from Marienburg in Boroussia about the Sun a little before his setting and the Moon's conjunction, and the Sun's Eclipse, (which yet was not seen by him.) I Saw at that time (saith the Observer) the Sun, in a sky everywhere serene enough, being yet some degrees above the Horizon, and shining very bright, yet lancing out very long and reddish rays, 40 or 50 degrees toward the Zenith (as appears Fig. 3.) Under the Sun, towards the Horizon, there hung a somewhat dilute small Cloud, beneath which there appear'd a Mock-Sun, of the same bigness (to sense) with the true Sun, and under the same Vertical, of a somewhat red colour. Soon after, the true Sun more and more descending to the Horizon, towards the said Cloud (as may be seen Fig. 4.) the Spurious Sun beneath it grew clearer and clearer, so as that the reddish colour in that apparent Solar disk vanish'd, and put on the genuine Solar light, and that the more, the less the genuine disk of the Sun was distant from the false Sun: Till at length the upper true Sun passed into the lower counterfeit one, and so remained alone; as appears Fig. 5. Which Appearance being unusual, and having never been seen by me, I took the freedom of imparting it unto you, especially since here the Mock-Sun was not found at the side of the true Sun, as 'tis wont to be in all Parhelia's seen by me, but perpendicularly under it; not to mention the Colour, so different from from that which is usual in Mock-Suns; nor the great length of the Tayl, cast up by the genuine Sun, and of a far more vivid and splendid light, than Parhelia's use to exhibit. Upon this appearance there soon follow'd here an exceedingly intense and bitter Frost, whereby the whole Sinus Puizenis was fro- zen up from this Town of Dantzick, as far as Hela in the Bal- tick Sea, which lasted unto the 25th of March; and the Bay was frozen so hard, that with great safety people run out into it with Sleds and Horses, for several of our Miles. Whether the recited Phænomenon have had any influence for this ex- treme Cold, I know not, but leave it for Astrologers to ex- amine. Whether the like Appearance have ever been observ'd in England, I should be glad to be informed of. An Extract of Monsieur Hevelius's Letter, lately written to the Pub- lisher, concerning the famous Kepler's Manuscripts; together with some considerations of his, about the use of Telescopic Sights in Astronomical Observations: Delivered in the same language, wherein 'twas written. Ex tuis 16. Septemb. datis intellecti, Te plenorem informati- onem de Kepleri Manuscriptis desiderare. Jam ante hac, ni fallor, ad Vos perscripsi, me omnia Kepleri MSS. ab hæredibus certo pre- tro (binuifse, tum opera jam edita, tum quædam hactenus inedita; inter cetera, ipsa Epiftolarum omnium (quarum magnus numerus) ad Clariss. Viros Scriptarum Autographa, cum plurimorum illius temporis Illuftrium Virorum reftponfionibus. Inter MSS. illa inveniuntur fane qua lucem me- rentur, non folum plurimæ Epiftola, fed & Opera quædam, inter qua ominet ejus Hipparchus, quamquam non fit, ut par eft digestus; qui tamen polet, a quipiam harum rerum perito & otio abundante, facile in ordinem redigi & abfolvi. Poffideo itidem scripta ejus Chronologica. At Kepleri vitam studio confpiriptam non invento; interim plurimæ notata digniffima, vitam ejus spectantia, paftim notavi, ex quibus Vita ejus polet haud obscure depingi. Quæ vero in specie ex scriptis ejus penes me habeo, Catalogus hicce * indicabit. Ceterum percipio, Veftrates * Vide infra. non omnes miti a stipulari in illo Dioptrarum negotio, de quibus in Machinae max Coelefis Organographia tradavi. Verum, eti- am Cl. Hookius, & Cl. Flamstedius †, aliique, plane aliter fentiant, e. perientia tamen quotidiana me edo- cuit, arque etiamnum docet, rem longe aliter fe habere in Magnis illis Organis, Quadrantibus Scilicet, Sextan- cos in Fixarum reftitutione habituri simus ab illo, qui nonnifi pinacidiis vitro- rum caflis utitur. Huc enim ex parte refpicit hujus Epiftola Author. † Vid. No. 96. pag 6000. ubi Flamstedius dubi- tat, an multum emendatores lo- cibus