Goofs

The size of the spider is extremely inconsistent. Sometimes is as big as a city, others it's only 2 stories tall.

In the first scene on the train, pushing the button at the back of the car led to a hammer coming down and the pool table turning over, leaving West upside-down under the train; the second time when West tells Artemus to push the button, it is obvious that no hammer came down, and West ends up on a cart right side up and attached to the tracks. The button should have done the same thing both times.

When Jim picks up the corset box with the pop out gun, the bullet is too big in diameter to fit the gun.

When Gordon projects Prof. Thadeus Morton's last conscious image, Morton's head is seen to be rotated clockwise, but the projected image turns opposite to what it should.

West strangles one of the machine room fighters with a chain, then throws him out the door. The chain's end is visibly loose. When West and Loveless fall, West grabs on to the man, who is now hanging by his chain from the spider.

It is highly unlikely that chain mail (which is all Gordon's "impermeable" amounts to) would actually hold against a bullet fired from close range. Even if it did, the impact would almost certainly break bones and cause severe trauma.

The collar magnets, high powered as they were, should have either attracted or repelled each other from the beginning. After Gordon hits West's collar with the rock, West's collar "reverses" polarity, causing it to attract to Gordon's. However, if there was a complete reversal as is implied, Gordon and West's collars should have repelled each other from the beginning. Therefore, Gordon and West should never have been able to jump into each other's arms, let alone stand next to each other in the small perimeter afforded them when they first woke with the collars.

The Golden Spike was actually 3 separate spikes: a gold spike from California, a silver spike from Nevada, and a gold/silver/iron alloy spike from Arizona. It was presented, but never driven into the roadbed. Some accounts say it was driven in and immediately removed.

In the first panoramic shot of Washington, D.C., the dome of the Capitol is still under construction during the administration of President U.S. Grant, after the Civil War. The dome was completed in 1864, in time for the second Lincoln inauguration in March 1865.

If the magnetic collar rings are strong enough to drag Artemus along the desert toward a railroad, then he would never have the strength to separate himself from James West.

James West left his black horse behind when he first boarded the moving train and has it later. While normally a train would have to stop to board a horse, it's quite possible the train has, as it does in the series, a corral designed to board horses while the train is in motion.

As the "tank" rolls up the riverbank (just before it massacred the Southern troops), you can see the "steel plating" bounce as if made of much lighter material and not soldered/welded on at all.

When Grant is driving the stake in at the railroad ceremony, the brand new railroad has very old, weathered sleepers (the wooden part between the rails).

When Jim is being towed behind the train and the cable snaps, he is shown accelerating towards Loveless' train, but in reality he would have been traveling in the same direction.

When Artemus is being pulled toward the railroad tracks by the magnetic collar a smooth trail from a previous take can be seen above his head.

When Artemus "hammers" West onto the pool table in the train you can see the felt flex as West lands on it. A slate top wouldn't flex, but the foam padding used to soften the landing would.

When Grant drives the stake in at the railroad ceremony, there is a clear shot of the flag in the background with 50 stars. From 1867-1877, the US flag had 37 stars.

In Loveless' office, Miss East quotes Rudyard Kipling's "The Ballad of East and West". However, this poem was published in 1889, whereas the film is set in 1869.

The movie is set in 1869, when the transcontinental railroad was completed. On the train, Artemus is seen next to a cylinder phonograph with a horn for sound. Edison didn't invent the phonograph until 1877 and it was not marketed to the public until the late 1880s. The type shown looks like the type sold in the 1890s.

As West is riding in the cart under the train, the track is clearly continuously welded rail, which was first used in the 1950s.

Loveless' wheeled vehicle was referred to as a tank, but the name "tank" for such a vehicle wasn't coined until the British used it as a cover name in the First World War.

When Jim West is hanging over the abyss, before the nitro destroys the saloon, you can see human legs between the legs of the horses.

At the end of the movie, West and Artemus are heading back to DC from Utah, which means heading East. However, they travel toward the sunset, which is to the West.

The joining of the trans-continental rail road was not at Promontory Point, but is fact at Promontory Summit.

Grant drove the golden spike at Powell County, Montana, after the completion of the Northern Pacific Railroad in 1883, not at Promontory Summit, Utah, in 1869.

We never see how West and Gordon survived the explosion of the building after the wagon of nitroglycerin hits it.

When West and Gordon are in the desert at night, West explains how the wasp kills the tarantula and then lays its eggs inside it. The wasp (a Tarantula Hawk Wasp) actually paralyzes the spider, but does not kill it. The spider is still alive when the eggs hatch and the young start to eat it from within.

Dr. Loveless claims he lost 35 feet of small intestine. The large and small intestine combined are less than 30 feet long.