Speaking in Tongues

With what sort of "tongues" did they begin speaking when "the Holy Spirit came upon them" (Acts 19:6)?
The Bible mentions two types of speaking in tongues as enabled by the Holy Spirit. The first type of speaking in tongues is the spontaneous ability to speak another known language, as happened at the Pentecost: "And they were all filled with the Holy Spirit and began to speak with other tongues, as the Spirit gave them utterance. And there were dwelling in Jerusalem Jews, devout men, from every nation under heaven. And when this sound occurred, the multitude came together, and were confused, because everyone heard them speak in his own language. Then they were all amazed and marveled, saying to one another, “Look, are not all these who speak Galileans? And how is it that we hear, each in our own language in which we were born?" (Acts 2:4-8). The second type of speaking in tongues is the Holy Spirit directly interceding for a Christian and sounds like "groanings" to our ears: "Likewise the Spirit also helps in our weaknesses. For we do not know what we should pray for as we ought, but the Spirit Himself makes intercession for us with groanings which cannot be uttered" (Romans 8:26).

Can the latter type of tongues be spoken in public?
Yes, but this type of speaking in tongues must be uttered through at most three Christians, each in turn, and they must be interpreted for the congregants to understand: "If anyone speaks in a tongue, let there be two or at the most three, each in turn, and let one interpret. But if there is no interpreter, let him keep silent in church, and let him speak to himself and to God" (1 Corinthians 14:27-28).

What about church services where more than three people are speaking in tongues and there is no interpretation?
The Holy Spirit never contradicts His Bible. Those speaking in "tongues" at such services are either faking it or the spirit speaking through them isn't the Holy Spirit. They are also liable to being seen as crazy: "Therefore if the whole church comes together in one place, and all speak with tongues, and there come in those who are uninformed or unbelievers, will they not say that you are out of your mind?" (1 Corinthians 14:23)

Doesn't 1 Corinthians 13:8-10 state the gift of speaking in tongues will cease when the Bible is completed?
1 Corinthians 13:8-10 states that the gift of speaking in tongues will cease when "that which is perfect has come": "Love never fails. But whether there are prophecies, they will fail; whether there are tongues, they will cease; whether there is knowledge, it will vanish away. For we know in part and we prophesy in part. But when that which is perfect has come, then that which is in part will be done away" (1 Corinthians 13:8-10).

Does "that which is perfect has come" refer to the completion of the Bible or to the second coming of Jesus?
The answer is found in the two verses that immediately follow the above passage: "When I was a child, I spoke as a child, I understood as a child, I thought as a child; but when I became a man, I put away childish things. For now we see in a mirror, dimly, but then face to face. Now I know in part, but then I shall know just as I also am known" (1 Corinthians 13:11-12).

Does a Christian see the Bible "face to face," or will a Christian see Jesus "face to face" upon His return?
 

Can a Christian say, "I shall know [the Bible] just as also am known [by the Bible]," or "[When Jesus returns] I shall know [Jesus] just as I also am known [by Jesus]?"