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Sextant

 

Method?1
Method 1 of 7:

Finding True North in the Northern Hemisphere

  1. 1
    Locate Polaris, the North Star.?Polaris is the brightest star in the constellation Ursa Minor, also known as the Little Bear or Little Dipper. The North Star is the tip of the Little Dipper’s handle, or the tail of the Little Bear.??is important to star navigation because it remains almost in the same spot all night.
    • The star is called Polaris because it appears within a degree of the Celestial North Pole and therefore appears to not move in the night sky.
    • In Greek mythology, Zeus rewarded two bears with a home in the stars of the night sky. When he threw them up there, he swung them by their tails, which elongated and formed the Ursa Minor constellation.
    • Today, most people refer to Ursa Minor as the Little Dipper instead of the Little Bear because the seven stars that make up the constellation look like a small water dipper.
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  2. 2
    Use pointer stars in the Big Dipper to find Polaris and True North.?Although Polaris is visible in the northern sky at most locations north of the equator, it can be hard to spot if you don’t know exactly what you’re looking for. Instead,??and find Merak and Dubhe, the two stars on the edge of the Big Dipper opposite its handle. Follow these stars toward the Big Dipper’s mouth to find Polaris.
    • If you go 5 times the Merak-Dubhe distance away from Dubhe, you’ll be within 3 degrees of Polaris. If Polaris is clouded over, you still know where it is.
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  3. 3
    Locate the Cassiopeia constellation.?Depending on your position, Cassiopeia appears as an “M” or a “W” in the sky. While Polaris is located at the North Celestial Pole, Cassiopeia is at the South Celestial Pole. Connect these two points to?.
    • When the Big Dipper is below the horizon, find the Great Square of the Pegasus constellation. Measure the distance from the star Alpheratz (visually a part of Pegasus but actually a part of Andromeda), to Caph, the star at the rightmost edge of Cassiopeia (W-shaped). In line with the 2 stars, measure another of these distances. You’ll then be less than 3 degrees from Polaris, even if you can’t physically see it.
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Method?2
Method 2 of 7:

Finding Latitude in the Northern Hemisphere

  1. Measure the angle between the horizon and a star directly above you.?For the best accuracy, use an??or?, which lets you read the angle off its curved section. This angle measure is the same as your latitude north of the equator.
    • If you don’t have an astrolabe or sextant, you can also?. Hold the??in front of you and align it to true north. Then, record the angle that is between a star and the horizon to get your latitude.
    • You can also find your latitude without the use of tools. Approximate the angle by extending your fist to the horizon and stacking fists hand-over-hand until you reach the North Star. Your extended fist is approximately 10 degrees of an angle measure.
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Method?3
Method 3 of 7:

Finding South in the Northern Hemisphere

  1. 1
    Locate Ursa Minor.?Known as the Little Dipper or the Little Bear, this constellation resembles a small ladle with 2 stars at the end of the handle.?, then find the star at the tip of the handle and draw an imaginary line from the star down to the horizon. The point where the line meets the horizon is south.
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  2. 2
    Find the Orion constellation.?Orion, or the Hunter, resembles a bent hourglass with stars making up Orion’s shoulders, knees, and belt. Find Alnilam, the middle star in Orion’s belt, and look for one moderately bright, one dim, and one fuzzy star hanging down from the belt. These represent Orion’s sword, which points south.
    • The stars Betelgeuse and Bellatrix represent Orion’s shoulders, and the stars Saiph and Rigel represent the knees or feet. Orion’s belt consists of 3 stars: Alnitak, Alnilam, and Mintaka.
    • In the Northern Hemisphere, Orion is visible chiefly in the winter and early spring but can be seen late at night in the fall or before sunrise in the summer.
    • The fuzzy “star” in Orion’s sword is actually the Great Nebula of Orion, an interstellar nursery where new stars are being formed.
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Method?4
Method 4 of 7:

Identifying South in the Southern Hemisphere

  1. Locate the Southern Cross constellation.?The Southern Cross, or Crux, is a constellation that can be seen in the Southern Hemisphere and some Southern areas of the Northern Hemisphere. Look south and locate the 2 brightest stars. Draw an imaginary line from one to the other, and this line will point south. To be more precise, extend the imaginary line until it intersects with the horizon. The intersection point is due south.?
    • The Southern Cross is made up of 4 stars total and looks like a diamond. Each of the 4 stars form a point of the cross.
    • While the Southern Cross is an important constellation (so much so that it is depicted on the flags of Australia and New Zealand), it is not particularly large. The bright pointer stars help differentiate the Southern Cross from the nearby (and slightly larger) False Cross.
    • Sigma Octantis is a star nearer to the South Celestial Pole than the Southern Cross, but it is too dim to help you find south.
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Method?5
Method 5 of 7:

Using Star Navigation in Both Hemispheres

  1. Find Sirius, the Dog Star.?Many stars are visible in both hemispheres, including the brightest star in the sky, Sirius. Locate south by drawing an invisible line from Sirius to the horizon and noting where it intersects.
    • You can also follow the same method using Orion’s Belt in both hemispheres.
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Method?6
Method 6 of 7:

Finding East or West at the Celestial Equator

  1. Locate the star Mintaka in Orion’s belt.?The torso of Orion resembles a bent hourglass, and Orion’s belt consists of 3 stars: Alnitak, Alnilam, and Mintaka. Mintaka is the rightmost star in the belt and rises and sets within a degree of true east or west.
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Method?7
Method 7 of 7:

Using Any Star’s Position to Navigate

  1. 1
    Drive 2 stakes into the ground.?The??should be about 1 yard (91 cm) apart. Then, tie a piece of??between them.
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  2. 2
    Select any star you see in the night sky.?While any star will work, it’s best to choose one that’s bright and easily visible. Then, line the star up with the tops of both stakes.
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  3. 3
    Wait for the stars to move out of position with the stakes.?Earth’s rotation from west to east causes the stars in the sky, as a whole, to rotate from east to west. The direction the star has moved in respect to its original position tells you which direction you’re facing.
    • If the star rose, you’re facing east.
    • If the star sank, you’re facing west.
    • If the star moved to the left, you’re facing north.
    • If the star moved to the right, you’re facing south.
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New handle for Sextant

 

I just finished a bigger handle for new sextant. If note the red button this for lighting the veneer and location for a battery using a CR2032 .
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Dave
Nes handle beside sextant?
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Better view of old handle?
Lathe turret

 

Here photos of a lathe turrets.
They great for small parts on projects.?
Most time you see a drill bits sticking out.?
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If tool right it is a great aid .
3 position works the best .
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Shaft work
1. BOX TOOL for turning down outside of shafts?
2. A threading die?
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ID work?
1.? CENTER drill
2. Drill?
3. TAP OR REAMER.??
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Dave?
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Navigation Columbus Curse

 
Edited

Columbus and Celestial Navigation used a Astrolabe and Dead reckoning tools.
Just think of taking a curse with Columbus in 1492

columbus-ship_sail.jpeg

.

At this time there was no real time keeping for Longitude.
download (8).jpeg

By this time they figure out latitude using a ASTROLABE and the sun move 23?° up and down in 365 days.
OIP (16).jpeg
?The Accuracy was lest than ?° off or (17 NM , 19.7 miles , 34.5KM) Even today's standards that is close.
The main way for Longitude was to use Dead Reckoning a hourglass and rope with knots at given spacing and board at end and a Compass.
Dead Reckoning old.jpeg

Nautical speed.jpeg


They plot out on paper there course. If they was off on ladatude correction was made. Depending the group measuring the spoed and number of course changes made per day and cross current errors.
Remember at this they did not of navigating on a round ball aka earth too.
OIP (16).jpeg

Old ships.jpg


This work very well till we had time accuracy keeping and one spot on earth??zero.

Here is the simple way of finding LONGITUDE.

Solar time different from your location and Greenwich Time in hours?X?15 is LONGITUDE?.

You are?10? hours?in time from Greenwich times?15 = 157.5° or 157° 30'

A sundiel could be used for time .
Screenshot_20250410-175656_Drive.jpg


LATITUDE
Some Astrolabe has a disk to adjust for the day year .
Depending on the that mader of the astrolabe is accuracy. Most re very good.
Astrolabe old.jpeg


A sextant takes in more factors but still at end simple except you chart for each day and you correction for very accurate angle
Video time

 
Edited

Using a ASTROLABE for finding time VIDEO
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Dave
How accrucy can get on open ocean

 

Here one how Accurate can is a compass.
This helps
The resolution on a digital component is 0.1° .
Using solar north a simple way of finding Longitude gives a location to at the Equator of lessthan 7 NM. The closer you get to poles greater accrucy.
This using a simple sundial solar noon only and very large compassion.
At 35° latitude accrucy within 3.9 NM .
Accrucy on Ladatude using a veneer type sextant with a 6 minute veneer is 6.8 miles.
On 6 min veneer can easily read to 3 minutes or 3.4 miles.
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Dave
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Order tools you may need NOW

 

This last chance to buy low cost tools for long time?
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Dave?
Re: 1903 Ohio shaper in operation

 

This was the first actual job on this mill was actually for this mill.
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The vise was a horrible import that was rendered into a useable one with a bunch of mods.
The jaws were surface ground, the moveable jaw was modified to to tighten the tolerances, a shoe was machined for the moveable jaw and a bronze thrust button was machined for the closing screw.
I added three hold down bolt homes to the front of it, machined registers on both ends of it and milled the hold down slot on the main casting to fix it to the table with a clamp below the top surfaces of the vise.
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Re: 1903 Ohio shaper in operation

 
Edited

Diamond 22 horizontal milling machine modifying a vise.
https://www.youtube.com/watch?v=ObC6a2vIe8g
Video on Unitmate Lathe running

 

Here is a ?nice Video on Unitmate mini lathe in use.
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I have not see this fetcher on mlnl lathe on a Unitmate mini lathe.?
This is from /g/Unimat/topics
I respect the other groups want to keep to subject.??
This group was formed to be a open subject group too.
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Dave?
Great replacement for GPS

 

Found great replacement for old dusty GPS .

This need no batteries and no Satellite need. It is made in brass with plating to keep brass look. Free shipping too.

You should buy two , one for a backup




Hight lite between brackets for PRICE
{?$11,075.00?}

Amazon & Walmart has a cheaper version too.

Dave
Time line of Navigation

 
Edited

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Here time line
??????

? ? ? Astrolabe first real Navigation tool ? ? ?
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The astrolabe is an intricate astronomical instrument invented in Ancient Greece around 150 BC. It enabled measurements of celestial objects like stars and planets, told time, determined latitude and longitude, and performed astronomical calculations. The astrolabe was a revolutionary navigation aid that utilized star positions to find one's position at sea. It remained the most widely used scientific instrument until the late 17th century1. The history of the astrolabe begins in Alexandria and moves to the Byzantine Empire and the Islamic world, where it flourished from India to Muslim Spain.?
bbb6f3790a62945956be86b5_rw_600.gif


????????
?? ? Dead Reckoning ?? ?

Dead reckoning was noted in the 1500's this does work for very low tech Longitude by using charts and compass. Basically give apx miles travel in a given direction. Then with know ladatude can give a close location. There variable that could 100s of miles off
OGC.gif
OGC(1).gif
OGC(2).gif


??????
? ? ? Sextant ? ? ???

The sextant's origins trace back to ancient times, but its modern iteration, commonly referred to as Hadley's Sextant, was created by John Hadley and Thomas Godfrey in 1730. The sextant is a navigation instrument used to measure the angular distance between two visible objects. The earliest known sextant was created by John Bird in 1757
sextant-animation-bild.gif


??????
? ? ? Time need for Longitude ? ? ???

John Harrison's invention of a chronometer that could keep time at sea with sufficient accuracy to be practical for determining longitude was recognized in 1773 as first enabling determination of longitude at sea. Later methods used the telegraph and then radio to synchronize clocks
OGC(4).gif



??????
? ? ? Just in time for? ? ?
?? ??Steam engines & Ships ???
OGC(3).gif
Calculation of Great Circle navigation

 

Calculation of Great Circle navigation.
If have a global and string you do same thing.
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You see photos of globals on ships some navigators will use pins on global for location and where going.? Cuts down noon on calculation.??
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Dave?
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Use Sextant for time

 

Link to web site for sextant for time.
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Dave?
Re: SEXTANT input data for locations #file-notice

 

Symbols and abbreviations for worksheet
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- Hs: Sextant height/altitude
- Ha: Apparent sextant height/altitude
- Ho: Observed sextant height/altitude
- Dip: Depression of the horizon
- Sun corr.: Sun’s altitude correction table
- Date: Date of the UT observation
- UT time: Universal time
- Index error: Refers to the alignment of its optical components
- Non adjustable error: Fixed error due machining issues
- ε: Index error plus non-adjustable error
- L: Estimated latitude
- G: Estimated longitude
- height of the eye: Height of the eye above the horizon
- LL/UP: Lower limb or upper limb of the sun
- GHA: Greenwich Hour Angle of the sun (whole hour)
- pp: Increment of the sun’s hour angle
- GHA: Greenwich Hour Angle of the sun (exact hour of the observation)
- P: Polar Hour Angle
- D: Declination of the sun (whole hour)
- corr.d : Change of declination per hour
- D: Declination of the sun (exact hour of the observation)
- Hc: Calculated height/altitude
- Z: true azimuth (o° to 180°) ancient notation
- Zv: true azimuth (0° to 360°) modern notation
- intercept: Ho- Hc
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SEXTANT input data for locations #file-notice

 

Here is a pdf file on the basic inputs used for location?
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1_ finding Longitude and Latitude Mar 30 2025_1_.PDF
1_ finding Longitude and Latitude Mar 30 2025_1_.PDF

Search Engine List

 

? ??
Search Engine in excel file below
?

General

Name Language Backend ownership
Multilingual Google
Baidu
Multilingual Brave
English
Multilingual Multiple, including Microsoft Bing
Multilingual Google and Microsoft Bing
Multilingual until 2021, then Elasticsearch
Multilingual Cloudview
? Multilingual Microsoft Bing
Multilingual Google
English Microsoft Bing
English and Kagi Inc
Multilingual Microsoft Bing
English
Multilingual Microsoft Bing
Multilingual Mojeek
Multilingual (Elasticsearch fork)
Multilingual Huawei
Multilingual Microsoft Bing
Multilingual
Multilingual Tencent
English Google
Multilingual Microsoft Bing
English Microsoft Bing
Multilingual
? Multilingual Microsoft Bing
Multilingual Yandex
? NetEase
English Microsoft Bing

? Main website is a portal

Geographically localized

Name Language Country
, ,
,
,
(defunct) ,
?
?
(defunct) ? ,
?
(Google backend)
,

Search Engine List Mar28 2025.xlsx
Search Engine List Mar28 2025.xlsx

Re: On the Funny Side

 



Just think of son's ? thinking each coin worth $3,500 each times 9 to 12.
O h$^% Dad might have more than 12 .

I go though allow the junk pile for $31,500 to over $42,500
Dam Dam Dam

He could stored the coins under bed like all other dad's do.
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Dave?
Re: Candle power engines.

 

Here one made by the Chinese?
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Dave?
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