How does an hourglass measure time?

The sand timer hourglass is sometimes referred to as a sand clock or a sandglass. Like other timepieces, it needs to be carefully calibrated. The hourglass maker must test the instrument and fine tune it to measure the correct length of time.

There are many factors that contribute to the ability of an hourglass to accurately measure time. The type and quality of sand is key. It must have a rate of flow that does not fluctuate. Sand that is too coarse will wear away the glass, eventually making the neck too large. Most important is the ratio of the neck (the hole, or tube) width to the diameter of the sand particles.

Here are the other factors that affect the accuracy of an hourglass:

The amount or volume of sand used

The size and angle of the glass bulbs

The quality of the sand or granular material. It must be fine, dry and consistently formed so it can flow smoothly. (Some substances used in the past were fine grain sand, powdered eggshells, and powdered marble.)

The width of the neck

A tight seal so no moisture can get into the chambers. Moisture can add weight to the sand or clog up the neck.

A flat and level surface on which to rest the hourglass

Like a foam roller, a massage ball can also be used to help release tension in our achy muscles after long hours spent in the office or after a workout. One of the differences being that it can get to those hard to reach areas such as the upper back, buttocks and feet. “Knots” or “trigger points” can be massive sources of pain in our bodies and using self-massage techniques can be very satisfying. Before diving in, there are a few important things to know which will help you achieve the best results.

Why a massage ball

Massage balls are affordable and small and therefore they can easily fit into a suitcase or handbag to use wherever you go. They also promote self-sufficiency so there is no need to rely on anyone else. Notwithstanding, it does not always give the same results as a traditional massage delivered by an experienced therapist

Find the right ball

There are many different types of massage balls ranging from very smooth and firm like a lacrosse ball to small and soft like a squash ball. Other balls include a tennis ball and the trusty spikey massage ball. To each his own but if you’re new to using a massage ball, perhaps start with a spikey ball or a tennis ball.

Where and when

Since they are so conveniently easy to use, you can use them almost anywhere for example against a wall, the back of a chair, on the floor or use your hands. Some office workers keep them at their desks as a reminder to use them during the day to help with releasing built-up muscle tension from poor posture or stress.

How

Start with only a few knots at a time, the most painful area being first. The idea is to trap the knot in the muscle with the ball and apply gently to medium pressure until the painful sensation has faded. Once you have the correct spot (and you will know when), hold it there and try to relax until only about 80% of the ache remains. When pressing too firmly, the sensation can be too painful for you to relax which defeats the purpose of using the massage ball in the first place, it could also potentially irritate the area. You are looking for a “good pain”.Roll the ball around to look for more tender spots or just enjoy gently going back and forth over the tight muscle. If you feel the muscle needs it, you can repeat it twice a day. After releasing the knot, follow it up with gentle stretches to the same muscle. It’s okay to lightly exercise the muscle afterward but avoid fatiguing it for 24 hours.

How does an hourglass measure time?