NavList:

Thanks Kermit for your interesting analysis. I thought of it as near simultaneous observations, perhaps a few minutes of time between shooting Altair and shooting the moon. Regarding the course and speed, the log gives us a course of S61°W, or 241° made good; also that in the 8-12 pm watch the logged distance was 21 miles, giving a mean speed of 5¼ knots. The southing component is thus only 2½ knots and has no significant impact on the "max altitude" vs "azimuth=180° " issue.

I would guess that the star altitude is recorded when peaking, but it seems strange that there was a 17 minutes of time delay until the moon observation. But we don't know the circumstances that evening.

Maybe captain Lundqvist's use of integer minutes of arc for latitude indicates some uncertainty in the star altitude, but this is pure speculation. As the moon was quite close to the prime vertical, a slight error in the latitude wouldn't affect the longitude that much.

Lars