The strange and dangerous voyage of Captaine Thomas Iames, in his intended discouery of the Northwest Passage into the South Sea VVherein the miseries indured both going, wintering, returning; and the rarities obserued, both philosophicall and mathematicall, are related in this iournall of it. Published by his Maiesties command. To which are added, a plat or card for the sayling in those seas. Diuers little tables of the author's, of the variation of the compasse, &c. VVith an appendix concerning longitude, by Master Henry Gellibrand astronomy reader of Gresham Colledge in London. And an aduise concerning the philosophy of these late discouereyes, by W.W.

For the Moones true place.

The Anomaly of the ☽ Center—	5.	59.	18.	2
The Prosthaphaeresis of the ☽ Center—	0.	0.	5.	36
The proportionall Scruples—	0.
The Anomaly of the ☽ orbe—	0.	5.	11.	30
The Aequated Anomaly of the ☽ orbe—	0.	5.	5.	54

The Prosthaphaeresis of the ☽ orbe subtr.—	0.	0.	24.	4.
The mid. mot. of the ☽ Longitude from the ☉.	2.	59.	39.	1
The true motion of the ☽ Longit. from the ☉.	2.	59.	14.	57
The mid. mot. of the ☉ from the true aequin.	3.	47.	51.	56
The true mot. of the ☽ from the true aequin.	0.	47.	6.	53
Therefore the ☽ true place was in ♉—	0.	17.	6.	53
For the ☽ Latitude
The middle motion of the ☽ Latitude.	4.	32.	8.	15.
The ☽ absolute Prosthaph. of her Orb subtr.	0.	0.	24.	4.
The ☽ true motion of Latitude.	4.	31.	44.	11.
The ☽ Northerne Latitude was.	0.	0.	9	5.
And her Reductiue Scruples Subtr.	0.	0.	0.	26.
But the ☽ true motion in her proper Orbe was	0.	17.	6:	53:
Therefore the ☽ true place reduced to the Eclipt	♉.	17.	6.	27.
And because the North Lat. of the ☽ was		0:	9:	5:
Therefore will her Right ascens be.		44:	35:	10
And her Declination—		17:	7:	49
And because we haue the distance of the Moone.
From the earth in Semidiameters of the earth	64	15
Therefore shall the ☽ apparent Semidiam: be—		0.	15.
And her parallax of Altitude.		0.	47.	0.
Now because the Altitude of the limbe of the ☽ was found by obseruation to bee—			29:	11:
If we shall substract her Semidiameter—			0:	15:
And the refraction—			0:	2:
We haue the apparent Altitude of the ☽ center—			28:	54:
To this if we adde the parallax of Altitude—			0:	47:
We shall haue the true Altitude of the ☽ Center:			29:	41:

Hauing thus the Latitude of the place, the ☽ true Altitude with her declination, by the resolution of a Sphaericall Trian∣gle according to the 11 Probleme, lib. 2. Part. 2. of our British Trigonometry we haue the distance of the ☽ from the Meridian—63: 26:

And by comparing this Arch with the difference of the ascentions of the Luminaries, the Time of the ☽ totall reco∣uery of her light at Charlton will be 7. hou. 49. min. 28. sec.

Which subtr. from the time of the Emersion at London. 13 hou. 7. min. 28. sec.

The difference of Meridians in respect of time will be 5: h. 18: m. o. So that Charlton is remooued from London West∣wards, 79. gr. 30. m.

This may likewise be confirmed by a second different ob∣seruation made at the instant of the Moones Culmination or Mediation of Heauen, at which time the Altitude of the brightest Starre in the Asterisme of the Northerne Crowne, (being of the second Magnitude) was found to be 33. gr. 27. m. Easterly. Ann. 1632. Iune 23.

It may be Problematically deliuered after this manner. Hauing the Latitude of a Place, with the Altitude of a knowne fixed Starre at the moment of the ☽ culmination, to finde the Longitude.

This fixed Starre is of knowne longitude and latitude, ther∣fore was his Declination 27: 59: and right ascension 229. 46. Now by the resolution of a Sphaericall Triangle of 3. knowne sides we haue the distance of this Star from the Meridian, and by consequence the right ascension of the ☽, whence we con∣clude her Culmination to be with the 28: 10: m. of ♑. but the Moones true place was much lesse. Here note that the scru∣pulosity of time is vnknowne, and therefore we cannot argue the ☽ true place from thence (though I grant it might be e∣uinced) for that were to begge the Question, and to know that first, which we looke after.

In the next place we are to inquire with what point of the Ecliptique the ☽ did culminate with vs here at London, that so from the difference of her places, of the like affection, we may deduce the difference of Meridians.

Obseruation on the ☽ Culmination here at London wee made none, therefore must we haue recourse to the aforesaid Tables of Lansberg, and from thence calculate the same. Now because the ☽ was not farre remooued from the ☉ opposite point. It will not be amisse to enquire first the ☽ place at midnight.

	Sex.	Gr.	M.	S.
The ☉ opposite place at midnight in ♑	0	11.	18.	15.
The ☽ true place at midnight reduced to the
Ecliptique was in ♑—	0.	23.	33.	18.

The South Latitude of the Moone was —	0.	4.	56.	38
Therefore the difference of Ascensions will be —		14.	6.	0
The Diurnall motion of the Moone —		14.	24	0
Therefore the Moones proper motion answerable to the difference of Ascensions is —		0.	33.	50
Which added to the Moones true place at midnight		23.	33.	18
Giues vs the Moones true place reduced to the Ecliptique at her Culmination at London —		24.	7.	8

Now because the ☽ Southern Latitude was 4. 56. 38, the Arch therefore of the Ecliptique comprehended betweene the Moones true place and the culminating point of the Eclipt. will Trigonometrically be found to be 54: m. 38. s. which ad∣ded to the ☽ true place before found giues vs the culminating point of the Eclipti. 25. gr. 1. m. 46. s. which is lesse then that found at Charleton: the difference being 3. 8. 24. therfore is the place of Obseruation Westerly of London. Hauing therefore the ☽ Diurnall motion and the difference of the culminating points we conclude the Meridian of Charlton to be distant frō this of Lōdon 5. h. 14. m. of time or 78. 30. of the Equator.

The difference betweene that of the Eclipse, and this latter obseruation is only 4. minutes of time or one degree, a dif∣ference easily pardoned, especially if wee shall compare the same with some other places, yea euen such as border neerely on each other. To giue an instance on 2 eminent places which lye in the heart of Europe, Rome & Norenberg: Their diffe∣rence of Longitude Regiomontanus makes 36. Werner 32. Appian 34. Maestlin and Origan 33. Stofler 18. Maginus 26. Schoner 12. Mercator and Hondius as much. Stadius 13. Ian∣sonius 10. Longomontaus 16. Lausberg: 10. Kepler by 2. obseruations on 2 Lunar Eclipses, but 4 minutes of time.

This varietie among these great Artists, will I hope par∣don vs this difference of 4. m. and be a means to incourage our English Sea-men and others, to make such or the like obserua∣tions in forraine parts as the heauens shall be offred vnto them.

H. GELLIBRAND.