A group of new packing-fraction-difference measurements are reported for the following elements: chromium, gadolinium, gold, lutecium, molybdenum, osmium, platinum, ruthenium, strontium, tantalum, tin, uranium, ytterbium and zirconium. By combining these differences with known packing fractions a number of new packing fractions are deduced. These are plotted on a packing-fraction curve. Atomic weights of osmium and lutecium are calculated. The atomic weight of osmium is still below the chemical value, while that of lutecium is shown to be the same as a recent chemical determination.