When a cat is dropped it always lands on its feet, and when toast is dropped, it always lands buttered side down. Therefore, if a slice of toast is strapped to a cat’s back, buttered side up, and the animal is then dropped, the two opposing forces will cause it to hover, spinning inches above the ground. If enough toast-laden felines were used, they could form the basis of a high-speed monorail system.

This theory works equally well with crackers. So to save money you miss out the toast, butter and cats
Also, should there be an imbalance between effects of the cat and the butter, there are other substances that have a stronger affinity for carpet
The probability of the carpet impact is determined by the following simple formula:

P=s * t(t)/tc

Where p is the probability of carpet impact; s is the “stain” value of the toast-covering substance- and indicator of the effectiveness of the toast topping in permanently staining the carpet (chicken tikka masala, for example, has a very high s value, while the s value of water is zero); tc and t(t) indicate the tone of the carpet and topping – the value of p being strongly related to the relationship between the colour of the carpet and topping, as even chicken tikka masala won’t cause a permanent and obvious stain if the carpet is the same colour.

So it is obvious that the probability of carpet is maximised if you use chicken tikka masala and a white carpet – in fact this combination gives a p value if one, which is the same as the probability of the car landing on its feet. Therefore a cat with chicken tikka masala on its back will be certain to hover in mid-air, while there could be problems with buttered toast as the toast may fall of the cat, causing a terrible monorail crash resulting in politicians saying hag it wouldn’t have happened if their party was in power.