Several different Type and Attribute combinations in the game of Yu-Gi-Oh seem perfect for each other. When you think of WATER, the perfect Types to go with it usually would be Fish, Sea Serpent, or Aqua. FIRE and Pyro are obvious candidates for a matching Type and Attribute combo. Dragons and Spellcasters also complement the LIGHT and DARK Attributes more often than not, and WIND Winged Beasts are a very fitting combination. When you think of EARTH as an Attribute, there are a few Types to come to mind, like Beast, Plant, and Warrior, for example, but the Type it has become connected to in terms of an actual Deck is Machine. In this article series, I want to cover the history of EARTH Machines in Yu-Gi-Oh, primarily focusing on the archetypes that would come together to closely exemplify what EARTH Machine is played as today, so an archetype like Qliphort will not be covered since that Deck has always done its own thing. I will go throughout the years to see EARTH Machine archetypes that have been able to play on their own or combine with other EARTH Machine strategies to make a competent Deck, and see how successful this Type and Attribute pairing has been throughout the years.
Introduction
In Part 1 of this series, I will cover the original EARTH Machine archetype in the game: The Gadgets. Specifically, to start, I want to go over the impact of the Gadgets in the OCG since the archetype was released overseas in 2004, long before they would be legal to play in the West in 2007. The Gadget archetype on release only consisted of three cards: Green Gadget, Red Gadget, and Yellow Gadget. These were three Level 4 EARTH Machine monsters with fairly low stats as Green Gadget sits at 1400/600, Red Gadget at 1300/1500, and Yellow Gadget at 1200/1200, but where the Gadgets lacked in stats, they made up for in utility. The three Gadgets were some of the earliest monsters in the game to add a monster from the Deck to the hand when they were summoned, with Green Gadget adding Red Gadget, Red Gadget adding Yellow Gadget, and Yellow Gadget adding Green Gadget. This utility would help a dedicated Gadget strategy keep up card advantage, always having a monster to summon on the next turn as long as you had Gadgets in the Deck and their summon was successful, with their effects not missing the timing since they are "when" effects. There were no other cards in the game at the time of the Gadgets' release that could keep up with card advantage like they could. 
Now, while they were able to keep card advantage like no other strategy at the time, the Gadgets weren't immediately impactful when released, mainly due to the overwhelming power of Chaos strategies at the time with powerful cards like Chaos Sorcerer, Black Luster Soldier - Envoy of the Beginning, and Chaos Emperor Dragon - Envoy of the End being too powerful for monsters like the Gadgets to keep up with, no matter how many of them you might have. Once the Forbidden section of the list was finally introduced and banned some of the most powerful cards that the Gadgets would struggle with, they were finally able to shine since the powerful cards being removed gave room for Decks to finally experiment with these Gadgets, and with this experimentation came several different ways for the Gadgets to be played.
Removal Gadget
The first style of the Gadgets was the most basic, simply relying on powerful Spells and Traps that excel at removing the opponent's monsters off the field so your Gadgets can have a clear shot for direct attacks. For example, you can summon a Gadget to search another Gadget and protect it with some of the strong removal Traps at the same time, like Sakuretsu Armor for defending against attacks from a stronger monster, and that being pushed further with the 1-of Mirror Force at the same time. Solemn Judgment, Bottomless Trap Hole, and Torrential Tribute could also prevent strong monsters from hitting the field, and you can add some burn with Ring of Destruction to speed up the damage output you put out. 
There are also really good Spells for taking care of the opponent's monsters, like Fissure, Smashing Ground, and even Hammer Shot to remove a single powerful monster the opponent might have, since this was a time when a lot of monsters wouldn't be summoned in a single turn. You also have Nobleman of Crossout to remove set monsters, especially powerful in an era where FLIP effects would still be relevant. The OCG also had Shield Crush, which was used as another answer for Defense Position monsters. Book of Moon could force monsters with high ATK into Defense Position, which would hopefully be low enough for a Gadget to run over. Creature Swap is also good to take your opponent's more powerful monster and give them a Gadget you already got your utility out of for searching. You could even run Shrink or Rush Recklessly when the opponent attacks to either make your Gadgets stronger or the opponent's monsters weaker, so you can hopefully win the battle.
Meta Gadget
The next version of Gadgets is the most flexible and the version hardest to define a single playstyle for, but it's Meta Gadgets. This version of Gadgets stocks up on meta cards for the time, relying on effects that can be strong against other meta strategies. Some of the most popular cards for this variant in 2006 would be Royal Decree to handle the high Trap count Decks you might run into, and Banisher of the Radiance against strategies relying on putting monsters in the graveyard, which is potent at a time when the Future Fusion and Overload Fusion play was popular to fill the graveyard with Machines to summon a gigantic Chimeratech Overdragon to push for game. You could also run several cards that excel in stopping the Special Summoning of monsters like Royal Oppression and later both Vanity's Fiend and eventually Fossil Dyna Pachycephalo. This version also has a weakness of using a ton of Deck space with the Gadgets and all the meta cards you would run to counter the opposition, along with cards that go good with the Gadgets in general. There were some strong cards at the time, like Hydrogeddon to get some field presence, Drillroid to handle Defense Position monsters, and the OCG even had Doomcaliber Knight at the time to stop any monster effect. The way the Deck is built depended on the environment it was played in, but it's another strong way to play Gadgets.
Hi-Beat Gadget
The next version of Gadgets tries to make up for the low ATK power of our trio, that being Hi-Beat Gadget. This variant of the Deck tried using high ATK monsters to make up for the offense that the Gadgets inherently lack. The aforementioned Overload and Future Fusion play could be used in Gadgets to make Chimeratech Overdragon, since the Gadgets themselves are also Machines to fuse with Cyber Dragon, which in of itself offers a strong 2100 ATK to get over most to all the Normal Summons in the game. You also have Cyber-Stein legal at the time to summon a powerful Fusion like Cyber Twin Dragon or Cyber End Dragon, for example, which can be combined with Megamorph to push for a potential OTK. You could also use Limiter Removal to make the stats of your Gadgets able to get over a ton of stronger monsters, and make the monsters you use to push for game even more lethal. This was a gimmick that eventually helped get Limiter Removal put to limited status for over a decade. It's another straightforward way to play Gadgets and possibly the easiest variant to close out games with.
Compensatory Gadget
The final version of Gadgets worth noting is the Compensatory Gadget variant, which focuses on using Ultimate Offering, and the name comes from the OCG's name of the card being Compensation of Blood. Ultimate Offering is a Continuous Trap that lets you pay 500 LP to gain an additional Normal Summon or Set of a monster during your Main Phase or opponent's Battle Phase. This combines well with the Gadgets constantly searching for each other upon Normal Summon, making it extremely easy to flood the field with Gadgets that can help you push for massive damage. It is an unstable version of Gadgets, since while you are summoning a ton of monsters, the stats on them still struggle to get over bigger monsters on the field without having good Tribute Summons to use your Gadgets for, or removal for the powerful monsters your opponent has. This variant of Gadgets wouldn't take off until the Xyz-era, when you had monsters in the Extra Deck you could use your Gadgets to make, but that's a story for another time.
Conclusion
The Gadgets were revolutionary in how monsters would be designed in the future, being able to add other monsters from the Deck to the hand. The Gadgets paved the way for the later release of a card like Elemental HERO Stratos to search the entire HERO archetype on his summon, let alone all the other archetypal monsters that search for other cards in their Decks on Normal or Special Summon. The Gadgets might be weak in terms of stats, but they were a strong meta strategy when released in the OCG, an era where we would be focused on playing Goat Format. Information like this can be hard to find, being mostly from Japanese websites from the 2000s I used the Wayback Machine to find. I didn't even find the Extra Decks for the Cyber-Stein lists, but it's easy to assume what was likely in there, especially in an era where you could play every Fusion in the game in your Extra Deck. The Gadget strategy can easily adapt with many cards to compensate for their stat weakness while making good use of their ability to keep up your card advantage, and the many ways the Gadgets would see play in the OCG would carry over to the TCG, but with a later release at the start of 2007 compared to the OCG getting these cards in 2004, the impact of the Gadgets would be somewhat different compared to if they released earlier in the West, but that's a story for the next part in the EARTH Machine series, analyzing how successful the Gadgets were when they released to the TCG.
