You can lift the oil bottle when it is poured, but if the bottle is poured without being tightened or if there are gaps in the bottle body or cap, the oil inside will slowly flow out, indicating that the bottle containing oil is safer when placed vertically. Similarly, if we place a hydraulic jack with hydraulic oil horizontally, this type of jack may also experience oil leakage, and in situations where the oil distribution is uneven, it is difficult for the jack to exert its driving force.

This is the shortcoming of hydraulic jacks. Considering the safety and efficiency of lifting operations, we should try our best not to let hydraulic jacks lift heavy objects while lying down.

If we need to lift heavy objects in the horizontal direction, we can choose to use a screw jack that relies on a mechanical power system instead of a hydraulic system to transmit force. The ratchet and pawl inside the screw jack, driven by the force transmitted by the handle, will turn small force into large force. This is purely the joint action of various mechanical components, without any oil involvement. Therefore, even when used horizontally, there is no need to worry about oil leakage or a decrease in lifting force.